SPEC has about 6 different materials available. If you need SPEC I can help you out....
I like the McLeod stuff also

I am not a big fan on the KC pressure plate, it slipped in the higher RPM's on my old 302 combo, it didn't have the pressure to hold the power 340RWHP. Walt @ Promotion has some nice clutches for Tremec's as well, and they seem to hold up nice you may want to try him also.