For new air-cooled parts locally, in addition to Tri-State Imports in Cleveland and Mainly Foreign in Chattanooga, there is a place in Dalton called American Foreign . . . locally, those are the big three. It's been two or three years since I've bought anything from them, but Al Johnson's VW dealership in Dalton did stock a LOT of air-cooled parts as well, and their prices were usually competitive with, or better than, those three parts stores.
Swap meets at shows are usually where you'll find your best bargins . . . prices are usually competitive with mail order, but you get to see the parts before you hand over hard earned cash and find the parts are junk when they arrive, PLUS you don't have to pay for shipping, and most of the time you won't be charged sales tax either.
If you end up going mail order, I like CIP1.com and Mid America Motorworks . . . but there are tons of choices when it comes to mail order.