Check Racing Junk.com regularly. You might find what you're looking for for a reasonable price. Too many unknowns. There are a few trucks on Racing Junk that look like someone put a travel trailer (which is essentially what you have) on a medium or heavy duty truck chassis.
Started looking for 379 Peterbilt TC, 24' to 30' box, bumper pull--but ended up w/1999 Liberty Coach conversion of 45' Prevost XLV bus. 1,000sf heated/AC'd race shop w/dump station, 50amp shore pwr where bus parks, 3 NASCAR/ARCA race cars & 26' Bravo trailer.