Small update, I've decided to keep my current manifolds/housings/internal WG's, just upgrading the head gasket, fixing the coolant lines, swain tech for all the exhaust components (previous ceramic coating was not rated high enough and flaked off) and bracing the driver side manifold.
Why brace the manifold? Here's mine after ~10k miles:
That highlighted area would be a crack. Every GTM manifold I've seen that has a few thousand miles on it cracks in this same spot.
The shops fabricator is going to repair this and then make a brace to help support the weight of the turbo from the block. I hope the new GTM manifolds everyone is waiting on no longer have this issue!