I have the Exedy Hyper Single and am very happy with it. After installation, there was a little bit of chatter but that went away completely after the clutch was broken in. When I need a replacement, I am going to stick with the same clutch if I can.
Here is a link where I posted a bunch of PICs and specs on the stock clutch and the Exedy Hyper Single.
P.S. I'd avoid ACT since others have not had positive experiences to report after installing.