Roll Cage design

[PoorMans180SX]

Well, I didn't get a lot from all that except that I'm overdesigning. I'm definitely sticking with X-door bars, and the corner reinforcements. Both are key to cage stiffness and safety. I'll take out one bar in the X in the halo, but a crossbar is necessary for stiffness. And I'll add a harness bar into my design. I'm not looking for "cool points" I'm looking for maximum chassis stiffness. What materials does everyone recommend then? Isn't Chromoly still the stiffest, safest, lightest metal to make cages out of? Sorry I'm not up to date on my latest cage requirements, I'm looking at NASA and SCCA specs now.

Another point I forgot: I know it would be best to triangulate the front strut towers with the dash bar horizontally (Or run a setup similar to DSG's Maxi) but it's basically impossible with the brake booster and clutch cylinder location and a VQ in the engine bay.