There's a shop with a pitiful selection in the acworth "town square", but it's almost not worth looking at. Another shop just opened by by the best buy on 41. They have a good selection of holsters, but they hadn't gotten all of their weapons out when I visited last, so i can't comment on weapon selection.
My suggestion:
http://www.gafiringline.com/
2727 Canton Rd. (Hwy 5), Suite #410
Marietta, GA 30066
Easiest way i've been getting there is by taking Berret Parkway up to Canton Rd. and taking a right. It's in the complex on your immediate right, i believe it's called "Piedmont Place" or something like that. I don't think the name has changed yet, so the sign might still say "Nick's Guns"
It's a little bit of a drive, but they have the best selection in the area and the new owner is a member of this forum. They used to have a pretty bad reputation, but Dan (the new owner) has REALLY cleaned the place up! They sell Sig Sauer and also have an indoor shooting range. Pricings are on the website.
Edit: According to their website:
We are a Sig Sauer "SigNificant Dealer".