when i was in SC, i would go to CPR in columbia. Last time i was there was back in late 2007 so i'm assuming they are still there. Chris Tuten ran the dyno/tuning, great guy.
Amazon Racing in Aiken SC is a great place too. Rick know's his stuff too.
Almost forgot...Badassperformance (Macon-Moore performance) Dave and Macon are great guys to deal with and it's in Sumter SC.
2014 Mustang GT, A6, Grabber Blue