I have the Exedy Stage 1 organic clutch in my GSR, has always held my 183whp/133wtq with no problems. And the stiffness is nearly stock, maybe a 5-10% stiffness increase, next to nothing. Whatever brand you go with, stay with "Stage 1" unless you clearly expect to go beyond X company's Stage 1 clutch handling capabilities with your future mods. Bigger isn't better with clutches, if something goes wrong, you
want the clutch to take the abuse, not your axles or tranny. When in doubt, go with the "weaker" clutch. Though those situations are rare that you should be torn between Stage 1 vs. 2 / 2 vs. 3, just read up on what each manufacturers whp ratings are for each of their clutches, and it shouldn't be hard to make the right decision.
My Exedy