Where is a good place to find designer prom dresses in alabama, Tennessee, nothern flordia, or georgia?

Yes i kow prom is a ways away but i want to go on and start looking for a dress mainly because last year me and another girl had the same dress and i waited till the last min. to get one. This year i wasnt something totally differant! So anywhere in alabama or georgia below atlanta would be good. Tenneesee ornorthern flordia.