Jaygnar-
You are in the heart of the greatest area of freshwater fish diversity in the temperate world. The Savannah has a great diversity of fishes, and the nearby Tennessee and Coosa drainages are even more absurdly diverse, comparable on a species/drainage area basis to the Amazon and Mekong. Even if you aren't an angler, it's a lot of fun to get out with a net and see what you can find. Hit small to moderate-sized streams for peak diversity and relative ease of capture.
Here are a few vendors that carry sunfish and other North American natives:
Sach's Systems Aquaculture- St. Augustine, FL. Probably the widest selection of any native vendor.
Jonah's Aquarium- San Diego, CA (I think; not quite sure on that one). Good selection of southeastern and midwestern fishes.
Zimmerman's Captive Raised Native Fish- Gambier, OH. Like the name says. Captive-raised fish and crayfish.
KSI Aquatics- Lexington, SC. They have fish available seasonally; concentration is on SC/GA fishes.
BTDarters- Port Washington, WI. No sunfish, but they do carry darters and other small community fishes, if you catch the native bug and want to set up more tanks.
For more info on native fishes, a classified section, and potential netting partners, visit
http://forum.nanfa.org.