Heh, I just skimmed your message and assumed you were talking about the black bimmer. D'oh!

Just remember that it's important to have sufficient dampers to go with your springs. I wouldn't be surprised if you ended up with some VERY stiff springs, especially on the track car. (800's?) Typical shocks won't like that very much. The good news is that Bilsteins are revalvable, so you can have them custom valved to match your spring rates and your intended use.