Just saw your post and have rowed both drifters and skiffs. Both are capable on the TN rivers you mentioned. If you can handle either the sportsman or the head hunter, you can certainly handle a full size drift boat. The 14' drifters weigh a little more than the others, but they also hold their value better and have plenty of room for you, Mrs. Trico as well as one other person (who can also row while you fish). The later is very important, just ask my friends who row while I fish!
Get something with some storage, the Hyde drifters have storage built in up front and have a bunch of different benches and pedistal storage. The more storage you have, the more stuff you bring and the more weight you have to move. Extra "stuff" can make the back sore if you aren't careful.
Get good oars. I reccomend cataract counter balanced oars. These will help your elbows and shoulders feel better at the end of the day. Also, they have a little less flex so when you make a move, change directions or generally need to get out of trouble, they will respond. The extra money for these is well spent.
Get an EZ Anchor Pulley for the rear. One that goes between the anchor and the arm. This will save your back when you pull the anchor, to make a move, for those fish that are rising just out of casting range. Also, for me a side pulley system works better than the floor mounted model. It is easier on my back to pull sideways than to pull straight up.
Last but not least is loading and unloading the boat. A tilt trailer is a luxury, but may be worth the extra cast on any boat. Especially at the end of a long float when all you want is some rest! An electric winch would be good for the takeout too as long as we are spending your money.
Hope some of this info helps and IMHO you can't go wrong with a drift boat, it has been the best purchase I have made yet for fishing.