I've used both MOAB Bike Shop in Murfreesboro and Endeavor Performance in Nashville.
If you're planning to race or have a tri-bike, and want a laser perfect fit and have some money to spend - Endeavor Performance is your place.
If you want to be super comfortable on your bike and have a perfect fit for that, and want to work with someone who will take super care of you (and cringe at the thought of driving to Nashville) - MOAB is your place.