I just finished this little beauty. It weighs just 660 lbs - can be towed by pretty much anything. Here are the specs:
5x8 - 660 lbs., floor, walls & ceiling all insulated, 80mph rated tires, queen size sleeping area 1000 watt hour power station & 200 watt solar panel on roof, 120v shore power, 5000 btu air conditioner, roof vent fan with smoke & carbon monoxide detector, tons of storage. Asking $5395/obo