If you're on top of clay (I'll remember the red clay from the south-eastern states for a looong time!) without water problems then that should greatly raise the efficiency of your setup
Just a thought: In Georgia you probably need more A/C than heating, or a similar amount, then what about dumping your A/C's waste heat into the ground. With the recieving end much cooler the unit's COP would be much higher, killing a second bird with the same stone (ground loop). Solar would just be an addition, so it wouldn't need to be too big.
BTW: The picture you attached got lost.