KZ makes several floor plans in the Sportsmen Classic and Spree Escape lines that could work. The Sportsmen Classic 19BHS sleeps up to 6, with 3500 lb GVWR, 20.5' long, 370 lb dry hitch (which will likely be closer to 500 lb loaded hitch, but still ok for payload). If you don't mind a hybrid, their 18RBT is only 336 lb dry hitch.
Jayco makes a good TT, the Jay Flight SLX 184BH with 300 lb dry hitch. Also hybrids like their Jay Feather Ultra Light X17Z.
Gulfstream has the AmeriLite 198BH.
You probably could buy any of these for mid teens, brand new, if you shopped around. Find one like this about 2 to 4 years old and you might be looking at $9k-$12K. Get yourself an outdoor screen room like the Coleman Instant or (better yet) the Clam to go along with your trailer, and you'll have a great setup.
