With few choices in our part of the world I went with JRE tune, but that was before Brian Tremblay in Laramie started his own shop. He used to be the LS guru at Laramie GM. One sharp dude. I'll be seeing him tomorrow in fact. But here's a link to a thread on JRE tunes. I'm happy with mine till I start doing more serious engine mods next year. Then it's going to Brian.
http://www.camaro5.com/forums/showthread.php?t=280051
Ted does it all by email and has done thousands of tunes.