I run a 24 PSI Stage 4 tune, and my Stage 2 Daily Driver has never slipped. My tune has moderate fueling so I don't know how happy it would be "all out", but I agree with the above poster, if you can buy more clutch than you need today, as tomorrow you may wish you had bought a heavier clutch.
EDIT: I failed to mention earlier while the clutch is being replaced, make sure you replace the fork, ball and clip. Otherwise the new pressure applied to the fork may either bend it or get stuck, and then you have to pull it all apart again. The last time I checked they were about $50.00, and I was so glad being told to replace them.