More the torque that requires a stronger clutch than hp. Those figures will come cheaper in an Evo I'd say?
Yeah I went with the "Super Single" version of the ClutchMasters 850 as it has great holding power, a bit better road manners than the twin disc and wears better. The 725 requires a pedal stop which is what put me off that, it's also a bit noisier. I'd have gone for the Sachs setup that Andrew and Tuffty run if I could have got the parts cheap, when I totalled it up, I was looking at near the money for this so seemed stupid not to get the 850SS. I've yet to finish the engine to try it out though but by all reports its a nice setup. I went with the steel flywheel too (again, better on the road and deals with heat better).
I also started a thread here on some strengthening parts for the 02M:
http://www.audi-sport.net/vb/a3-s3-forum-8l-chassis/220189-02m-strengthening.html