You might want to consider a Centerforce clutch. http://www.centerforce.com/
Spec seems to be talked about a bit on these boards, but the 2 best mechanic/racers I know both are overwhelming fans of Centerforce for our applications... at least for daily driver cars. They find Specs to be less than forgiving and friendly out in the stop-and-go world.
Wait a minute... your sig lists you at over 600 RWHP... er, ok, maybe you need the kryptonite clutch.