Bought a 2004 Duramax (LB7) with 14,000 very happy with it so far. Was wondering what aftermarket kit to go with Edge, Banks, Bullydog? which one will do less damage to my truck and give me the best power/fuel economy?

Edge is the most popular for an LB7.

I'd tell you to do a search, but you'd probably get so many results, it'd take you a week to read half of them.:D