Id pick a reputable shop that has the firsthand experience with LSx cars and just buy a package from them. One shop ive heard good things about is
www.texas-speed.com, just call them and see what they say. Or another good one is
www.vengeancerd.com, its not gonna be as easy as just picking a cam and throwing it in there and being good to go. Your gonna have to make sure the clearances on the p to v are good, probably need to have it tuned, worse gas mileage, driveability issues, etc. Just go to
www.ls1tech.com and do alot of reading and inform yourself as to what your looking at.