So there hasn't been any development in four months or so, and I believe that I have the answer I was looking for. Just in case anyone else runs into the issue I did, I'm going to risk posting my own answer.
The main issue is that of the $(-1)^{2j}$ term coming from the Lorentz covariance algebra. For this I am relying on Weinberg's "Feynman Rules for Any Spin", Phys Rev 1964 B1318 1964, Streater and Wightman's "PCT, Spin, Statistics, and All That" Princeton University Press, 1980 pages 14-16, and Novozhilov's "Introduction to Elementary Particle Field Theory" Pergamon Press, 1975 pages 75-77.
Starting with Weinberg, we want to construct our creation and annihilation operators, and thus our fields, in a Lorentz covariant way. He does this by having the operators obey transformations in the proper homogeneous orthochronous Lorentz group.
$$
x^\mu\rightarrow \Lambda^\mu_{\space\space\nu}x^\nu = g_{\lambda\rho}
$$
$$
g_{\mu\nu}\Lambda^\mu_{\space\space\nu}\Lambda^\nu_{\space\space\rho} \tag{Weinberg (W) 2.1}
$$
$$
det\Lambda=1; \Lambda^0_{\space\space 0}>0
$$
In Einstein summation notation.
For each transformation $\Lambda$ there corresponds a unitary operator acting on Hilbert space with the group property
$$
U[\Lambda_2]U[\Lambda_1]=U[\Lambda_2\Lambda_1] \tag{W 2.3}
$$
We next describe the action of these $U[\Lambda]$ on one particle $|\textbf{p},\sigma\big>$ states. We first define these states as the result of a boost ($\Lambda = L(\textbf{p})$ which takes a particle of mass m at rest to momentum $\textbf{p}$) on a rest state $|\sigma\big>$
$$
|\textbf{p},\sigma\big> = [m/\omega(\textbf{p})]^{1/2}U[L(\textbf{p})]|\sigma\big> \tag{W 2.6}
$$
This allows us to see how these states should transform under an arbitrary $\Lambda$
$$
\begin{align*}
U[\Lambda]|\textbf{p},\sigma\big> &= [m/\omega(\textbf{p})]^{1/2}U[\Lambda]U[L(\textbf{p})]|\sigma\big> \\
&=[m/\omega(\textbf{p})]^{1/2}U[L(\Lambda\textbf{p})]U[L^{-1}(\Lambda\textbf{p})\Lambda L(\textbf{p})]|\sigma\big> \\ &= [m/\omega(\textbf{p})]^{1/2}\sum_{\sigma'}U[L(\Lambda\textbf{p})]|\sigma'\big>\times \big<\sigma'|U[L^{-1}(\Lambda\textbf{p})\Lambda L(\textbf{p})]|\sigma\big> \\ &=[\omega(\Lambda\textbf{p})/\omega(\textbf{p})]^{1/2}\sum_{\sigma'}|\Lambda\textbf{p},\sigma'\big>\times D_{\sigma',\sigma}^{(j)}[L^{-1}(\Lambda\textbf{p})\Lambda L(\textbf{p})]
\end{align*} \tag{W 2.8}
$$
$L^{-1}(\Lambda\textbf{p})\Lambda L(\textbf{p})$ is actually the pure rotation $R$, otherwise known as a "Wigner rotation," and so $D_{\sigma',\sigma}^{(j)}[R]$ are here the $2j+1$ dimensional unitary matrix representations of the rotation group.
To now assert the Lorentz covariance of the fields, we say their creation and annihilation operators transform as above:
$$
U[\Lambda]a^*(\textbf{p},\sigma)U^{-1}[\Lambda]=[\omega(\Lambda\textbf{p})/\omega(\textbf{p})]^{1/2}\sum_{\sigma'}D_{\sigma',\sigma}^{(j)}[L^{-1}(\Lambda\textbf{p})\Lambda L(\textbf{p})]a^*(\Lambda\textbf{p},\sigma')\tag{W 2.11}
$$
And with the adjoint:
$$
U[\Lambda]a(\textbf{p},\sigma)U^{-1}[\Lambda]=[\omega(\Lambda\textbf{p})/\omega(\textbf{p})]^{1/2}\sum_{\sigma'}D_{\sigma',\sigma}^{(j)}[L^{-1}(\textbf{p})\Lambda^{-1} L(\Lambda\textbf{p})]a(\Lambda\textbf{p},\sigma')\tag{W 2.12}
$$
It is imperative that we get the forms of these to match, since the solution to my problem lies in the manipulation of these matrix coeffients $D_{\sigma',\sigma}^{(j)}[L(\textbf{p})]$ and their cross products in the eventual (anti)commutator. As such, we need make the following changes, using:
$$
\begin{align*}
&D^{(j)}[R]^*=CD^{(j)}[R]C^{-1} \\
&D_{\sigma',\sigma}^{(j)}[R]=\{CD^{(j)}[R^{-1}]C^{-1}\}_{\sigma,\sigma'}
\end{align*} \tag{W 2.13,2.15}
$$
We transform $W 2.11$ into
$$
\begin{align*}
&U[\Lambda]a^*(\textbf{p},\sigma)U^{-1}[\Lambda] \\ &=[\omega(\Lambda\textbf{p})/\omega(\textbf{p})]^{1/2}\sum_{\sigma'}\{CD^{(j)}[L^{-1}(\textbf{p})\Lambda^{-1} L(\Lambda\textbf{p})]C^{-1}\}_{\sigma,\sigma'}a^*(\Lambda\textbf{p},\sigma')
\end{align*}\tag{W 2.16}
$$
Now $b^*(\textbf{p},\sigma) $ transforms as $a^*(\textbf{p},\sigma)$, so we can use $W 2.16$ for the antiparticle creation operator, and $W 2.12$ for $a(\textbf{p},\sigma)$,the particle annihilation operator.
Weinberg next forms our $(j,0)$ representation from the standard sums of Lorentz $K$ and $J$ operators, leading us to the following useful identity:
$$
D^{(j)}[\Lambda]=\bar{D}^{(j)}[\Lambda^{-1}]^\dagger \tag{W 2.38}
$$
Next we make use of the group property $\{W 2.3\}$ of the Lorentz group to split the Wigner rotations appearing in our formulae into three parts
$$
D^{(j)}[L^{-1}(\textbf{p})\Lambda^{-1} L(\Lambda\textbf{p})] = D^{(j)-1}[L(\textbf{p})]D^{(j)}[\Lambda^{-1}]D^{(j)}[L(\Lambda\textbf{p})]$$
Allowing us to write our previous transformation laws $\{W 2.12\}$ and $\{W 2.16\}$ as:
$$
\begin{align*}
&U[\Lambda]\alpha(\textbf{p},\sigma)U^{-1}[\Lambda]=\sum_{\sigma'}D_{\sigma,\sigma'}^{(j)}[L(\Lambda^{-1})]\alpha(\Lambda\textbf{p},\sigma') \\ &U[\Lambda]\beta(\textbf{p},\sigma)U^{-1}[\Lambda]=\sum_{\sigma'}D_{\sigma,\sigma'}^{(j)}[L(\Lambda^{-1})]\beta(\Lambda\textbf{p},\sigma') \\ &\alpha(\textbf{p},\sigma)\equiv[2\omega(\textbf{p})]^{1/2}\sum_{\sigma'}D_{\sigma,\sigma'}^{(j)}[L(\textbf{p})]a(\textbf{p},\sigma') \\ &\beta(\textbf{p},\sigma)\equiv[2\omega(\textbf{p})]^{1/2}\sum_{\sigma'}\{D_{\sigma,\sigma'}^{(j)}[L(\textbf{p})]C^{-1}\}_{\sigma,\sigma'}b^*(\textbf{p},\sigma')
\end{align*}
$$
Only one more Weinberg step left. We express our field as a fourier transform on the sum of lorentz invariant creation and annihilation operators $\alpha$ and $\beta$, and then substitute back in for $a$ and $b^*$:
$$
\psi_{\sigma}(x)=\frac{1}{(2\pi)^{3/2}}\int\frac{d^3\textbf{p}}{[2\omega(\textbf{p})]^{1/2}}\sum_{\sigma'}\left[\xi D_{\sigma,\sigma'}^{(j)}[L(\textbf{p})]a(\textbf{p},\sigma')e^{ip\cdot x}+\eta\{D^{(j)}[L(\textbf{p})]C^{-1}\}_{\sigma,\sigma'}b^*(\textbf{p},\sigma')e^{-ip\cdot x}\right]
$$
The (anti)commutator which we want: $[\psi_{\sigma}(x),\psi^\dagger_{\sigma'}(y)]_\pm$, will now return only those terms like: $D_{\sigma,\sigma'}^{(j)}[L(\textbf{p})]D_{\sigma,\sigma'}^{(j)}[L(\textbf{p})]^\dagger$ for the particle case "a," and terms like: $\{D^{(j)}[L(\textbf{p})]C^{-1}\}_{\sigma,\sigma'}\{D^{(j)}[L(\textbf{p})]C^{-1}\}^\dagger_{\sigma,\sigma'}$ for the antiparticle case "b."
Returning to $\{W 2.15\}$, we have:
$$
\begin{align*}
&D_{\sigma',\sigma}^{(j)}[R]=\{CD^{(j)}[R^{-1}]C^{-1}\}_{\sigma,\sigma'} \\
&\{C^{-1}D^{(j)}[R]C\}_{\sigma,\sigma'}=\{C^{-1}CD^{(j)}[R^{-1}]C^{-1}C\}_{\sigma,\sigma'} \\
&\{C^{-1}D^{(j)}[R]C\}_{\sigma,\sigma'}=D^{(j)}[R^{-1}]_{\sigma,\sigma'}
\end{align*}
$$
We can now group terms from the antiparticle case as so:
$$
\begin{align*}
&\{D^{(j)}[L(\textbf{p})]C^{-1}\}_{\sigma,\sigma'}\{D^{(j)}[L(\textbf{p})]C^{-1}\}^\dagger_{\sigma,\sigma'} \\
&=\{D^{(j)}[L(\textbf{p})]C^{-1}\}_{\sigma,\sigma'}\{D^{(j)}[L(\textbf{p})]^\dagger C^{-1\dagger}\}_{\sigma,\sigma'} \\
&=\{D^{(j)}[L(\textbf{p})]C^{-1}\}_{\sigma,\sigma'}\{D^{(j)}[L(\textbf{p})]^\dagger C\}_{\sigma,\sigma'} \\
&=D^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}\{C^{-1}D^{(j)}[L(\textbf{p})]^\dagger C\}_{\sigma,\sigma'} \\
&=D^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}D^{(j)}[L(\textbf{p})^{-1}]^\dagger_{\sigma,\sigma'} \\
&=D^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}\bar{D}^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}
\end{align*}
$$
Where the last step was by applying $\{W 2.38\}$. This gives us now for the (anti)commutator a form like:
$$
[\psi_{\sigma}(x),\psi^\dagger_{\sigma'}(y)]_\pm=\frac{1}{(2\pi)^3}\int\frac{d^3\textbf{p}}{2\omega(\textbf{p})}\left[|\xi|^2 D^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}D^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}e^{ip\cdot (x-y)}+|\eta|^2D^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}\bar{D}^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}e^{-ip\cdot (x-y)}\right]
$$
We now turn to Novozhilov, who indicates that in his nomenclature:
$$
D^J(\frac{p}{m})=e^{\frac{\beta(\textbf{J}\cdot\textbf{p})}{|\textbf{p}|}}, \theta^i=\beta\frac{p^i}{|\textbf{p}|} \tag{Novozhilov 4.80}
$$
Which is the same form as in $\{W 2.39, 2.40\}$, where
$$
\begin{align*}
&D^{(j)}[L(\textbf{p})] = e^{-\hat{p}\cdot\textbf{J}^{(i)}\theta} \tag{W 2.39} \\
&\bar{D}^{(j)}[L(\textbf{p})] = e^{+\hat{p}\cdot\textbf{J}^{(i)}\theta} \tag{W 2.40}
\end{align*}
$$
This implies, that by group property we can perform the following:
$$
D^{(j)}[L(\textbf{p})]\bar{D}^{(j)}[L(\textbf{p})]\equiv D^{J}(\frac{p}{m})D^{J}(\frac{-p}{m})=D^{J}(\frac{p}{m})D^{J}(\frac{p}{m})D^{J}(-1)
$$
Leaving us with
$$
\begin{align*}
&[\psi_{\sigma}(x),\psi^\dagger_{\sigma'}(y)]_\pm=\frac{1}{(2\pi)^3}\int\frac{d^3\textbf{p}}{2\omega(\textbf{p})}\Pi(\textbf{p})\left[|\xi|^2 e^{ip\cdot (x-y)}\pm|\eta|^2{D}^{(j)}[-1]_{\sigma,\sigma'}e^{-ip\cdot (x-y)}\right] \\
&\Pi(\textbf{p}) \propto D^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}D^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}
\end{align*}
$$
Novozhilov directly states that $D[-1]=(-1)^{2j}$ $\{page 77, in text\}$, but stops short of why. Which is where I turn to Streater and Wightman. In their book PCT, Spin and Statistics, and All that $(2000)$, page 15, they posit a form for these matrices $D^{(j)}$:
"Consider a set of quantities $\xi_{\alpha_{1}...,\alpha_{j},\dot{\beta}_1...\dot{\beta}_j}$, where the $\alpha$'s and $\dot{\beta}$'s take the values 1 and 2, and $\xi$ is symmetric under permutations of the $\alpha$'s and also under permutations of the $\dot{\beta}$'s. For each $A\in SL(2,C)$ we define a linear transformation of the $\xi$'s according to
$$
\xi_{\alpha_{1}...,\alpha_{j},\dot{\beta}_1...\dot{\beta}_k} \longrightarrow \sum\limits_{(\rho)(\dot{\sigma})}A_{\alpha_1\rho_1}...A_{\alpha_j\rho_j}\bar{A}_{\dot{\beta}_1\dot{\sigma}_1}...\bar{A}_{\dot{\beta}_k\dot{\sigma}_k}\xi_{\rho_{1}...,\rho_{j},\dot{\sigma}_1...\dot{\sigma}_k}
$$
[The dot over the index simply means that this index transforms according to $\bar{A}$ instead of $A$; the symbol ($\rho$) stands for $\rho_1...\rho_j$; the symbol ($\dot{\sigma}$) for $\dot{\sigma}_1...\dot{\sigma}_k$] This representation of SL(2,C) is usually denoted $\mathfrak{D}^{(\frac{j}{2},\frac{k}{2})}$. Every irreducible representation is equivalent to one of these."
From here, if we consider the case with $A\longrightarrow(-1)$ and $\mathfrak{D}^{(\frac{j}{2},0)}(A)\equiv D^{\frac{j}{2}}(A)$, then we can see that this transformation reduces to a multiplication by the inverse unit matrix $\textbf{-1}$ j times.
We're getting $\xi_{\alpha_{1}...,\alpha_{j},\dot{\beta}_1...\dot{\beta}_k} \longrightarrow \sum\limits_{(\rho)(\dot{\sigma})}-1_1\times...-1_j \xi_{\rho_{1}...,\rho_{j},\dot{\sigma}_1...\dot{\sigma}_k}$ or
$$\xi_{\alpha_{1}...,\alpha_{j},\dot{\beta}_1...\dot{\beta}_k} \longrightarrow \sum\limits_{(\rho)(\dot{\sigma})}(-1)^j \xi_{\rho_{1}...,\rho_{j},\dot{\sigma}_1...\dot{\sigma}_k}
$$
At this point there is a difference in notation, with Streater and Wightman using $\frac{j_{integer}}{2}$ to label their representations, and Weinberg and Novozhilov using $j$ either whole or half integer. Since these are functionally equivalent, then $\mathfrak{D}^{(\frac{j}{2},0)}(-1)_{Streater}\equiv D^{j}(-1)_{Weinberg}\equiv (-1)^{2j}$.
And finally, this leads us to the result:
$$
\begin{align*}
&[\psi_{\sigma}(x),\psi^\dagger_{\sigma'}(y)]_\pm=\frac{1}{(2\pi)^3}\int\frac{d^3\textbf{p}}{2\omega(\textbf{p})}\Pi(\textbf{p})\left[|\xi|^2 e^{ip\cdot (x-y)}\pm|\eta|^2(-1)^{2j}_{\sigma,\sigma'}e^{-ip\cdot (x-y)}\right] \\
&\Pi(\textbf{p}) \propto D^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}D^{(j)}[L(\textbf{p})]_{\sigma,\sigma'}
\end{align*}
$$
Leading us directly to the conclusion it always does: $|\xi|^2=(-1)\pm|\eta|^2(-1)^{2j}=\mp|\eta|^2(-1)^{2j}$, the spin statistic theorem.