Ive bought some turbo gear from schwartz
http://www.schwartzperformance.com/ and he is top notch.... he builds great engines, both turbo and non turbo...
He has a 730 Hp Ls7 that would be on my short list if my money tree wasn't defoliated from building a second floor..... and his turbo systems are built to last, and not built with thin walled gazillion dollar headers that crack from thermal stresses