If you want this as a track car, you are spending too much time worrying about visual items... just drive it man!
Ditch those rims, as they are probably the worst for anything performance related because they weigh about as much as a truck. Get something lighter.
I'd suggest buying some 330 brakes from one of the partout sponsors on here, those coupled with some good quality pads are going to be more than enough for what you will need them for.
You mention wanting to put on M3 bumpers and stuff on... well you already have an M3 bumper, or at least what looks like one in the pics, so that maybe explains why there are no supports and everything is missing from underneath.
Good idea to focus on suspension, and probably another good idea is to get some new bushings to start tightening things up like urethane FCABs and such... since you mention about not adjusting coilovers, Bilsteins will be fine like suggested... but any fancier adjustable shock based coilover like Ground Control or TC Kline potentially yields a better handling car.
Your projected horsepower numbers are a bit optimistic. Try looking at another car if you want that much power... its probably cheaper down the road.