I just edited my post - we're on vacation, and we're looking for a place where we can rent horses for a few hours. If we had our own horses down here, that would make life so much easier. There's so many good state forests to ride in!
I don't know much about the stables, but we have ridden our own horses there and it is very lovely. You will see a wide variety of wildlife, including deer and bear.
It is just north of Orlando, west of Sanford on Hwy. 46.