A 20 gauge Parker or Fox, if it fits you, would be an appropriate choice for a Georgia plantation hunt, I would think. As noted above, these will have a bit more drop at heel and comb than newer guns; but you may actually prefer more drop, as do I. It won't beat you death as a game gun, but if you use it a lot for extended rounds of clay games, I suppose it might become noticeable. Best thing to do is handle as many different guns as you can. You'll develop a preference.
Also, you'll want to consider whether or not you want to go with single or double triggers; I always liked double triggers, but they take some getting used to.
