No recent experience here and I'm sure some of the TN folks will jump in. Walter State would be my pick for the "best" baseball program based on history of draft and making it to the NJCAA world series.
Hiwassee College which is in E Tennessee and is an unknown to some but gets my vote! It's in an amazingly beautiful area. The coach is an energetic and absolutely honest guy - that is not a given in college coaching. The baseball program isn't as well known as many, but the field is respectable. It doesn't compare to Walter's State, but it works. They have a locker room/offices at the field. No indoor facility unless it's recently happened, but a gym that is used. The administrators of the school are down to earth. My son was originally going to go there and when we went for orientation, the college president had lunch with me! Where does that happen?!?! They have dorms on campus, so housing isn't an issue. Unfortunately they are not fully funded, so a full ride as compared to many other JUCOs isn't likely.
Tenneesee is a great location to play ball IMO. Warmer days fairly early, but not the temps of Alabama/Georgia/Florida, etc.