Would 15" knock-offs fit using C5/C6 suspension/brake components? I doubt it. Unless you move up to 17's, then it wouldn't seem fitting (no pun intended). But if one was okay with the larger wheels, why wouldn't you want to benefit from one of the better "stock" suspension/brake configurations out there?
John, I wish you all the best with this venture. I have seen a Hurricane up close and, quite honestly, I was a bit appalled by some of the fit and finish (especially around the trunk area...big gaps). I'm confident that you have the skills to address these items and make for a more formidable car for Cobra enthusiasts. Your one-off car looks scary fast...I don't think I have the huevos to get into that. Maybe in another life.
-Dean