I haven't done that trip either, but I've been looking some of that area over. One thing about Tennessee, if you're not familiar with it there aren't always places to randomly land on shore. You may have a stretch where it's just too rocky along the shore line to really land and get off the boat.
Tow Boat US operates on Chickamauga Lake from the Harrison Bay area. Not sure how far downriver they run, so a quick call to them might be worth it.
The river is navigable the entire route, and even accommodates commercial traffic. There are a couple of shoals and flooded timber areas you'll want to be aware of, so make sure you look at a chart (Navionics online or something like that) at a minimum. Not too much along the lines of services on the way, but should be plenty of boat ramps. Cotton Port is supposed to have fuel and food! (Not that I typically like marina food 'round here

). 16 miles (ish) from Cotton to the dam. And coming in to Watts Bar Lake, your first marina is a little ways in (another 6 miles or so from the dam). There was one closer to the dam, but I think it's closed now.
Making lockage through the dam may take a while. You should read the TVA lockage website if you're not familiar with that process. I've not actually gone through one yet, but it can take upwards of an hour to get through. Commercial traffic generally has priority in TVA locks, though I doubt that one is too busy.
Unless you land on the wrong farmer's field coming through there, you shouldn't have to squeal like a piggy.