If you have the bank, then an RPS BC2 is hands down the best twin you will find. You may crap your pants when you see what they cost, though... If you plan to drag race, it's the best. It will slip if you want it to, and it will bite hard if you want it to. The other advantage is the carbon material works to your advantage on launching, as it actually clutches to help get your 60' down. Carbon doesn't wear near as fast as organic/metallic materials, either, plus it can't warp. It's just obnoxiously expensive. You can find one for about $2000 if you hunt, but you will never have to change your clutch again.
You need a good tuner who can set up a very aggressive idle control strategy, because the clutch weighs significantly less than stock.
Here's a good write-up:
http://www.hotrod.com/techarticles/d..._clutches.html