there is only one subspecies of sirtalis native to Georgia... easterns! Thamnophis sirtalis sirtalis... so if you can keep other subspecies, then a red or a blue garter is a real possibility for you. Otherwise you are rather limited of you want red or blue... the vast majority of red and blue garters occurs in sirtalis! There are red coast garters and red plains, but they are rather hard to come by...