LT4 clutch if u plan on having less than 400 hp and want to keep the clutch as smooth as stock..
Brother had a centerforce... loved it for about 6000 miles until it crapped out on him..
Heard decent things about ram clutches.
My spec stage III exploded on me and blew my bellhousing apart along with the surrounding area.

If your mods an LT4 clutch would be great.. and its not too much money.