Coilover support bars, how much interest?

The issue of twisting the the frame rails could be solved with a strut tower brace like those used in many newer cars.
Obviously different engine combinations are going to have different clearance issues up top, this part would likely have to be built specific to each persons needs.
You could also brace the coilover supports to the firewall or maybe the rad support with bolt in braces.

For lower control arms, CAP was making a lower arm that attached to both sides of the K frame rather than just the backside. I would hope QA1 will continue with this design for use with their K frames.