Build a new frame for your existing camper. Build a receiver into the back of it for a two bike mount. Then place a water or fuel storage system on the tongue for an adjustable weight bias to keep your tongue weight in line. Something as simple as 6 or 8 scepter/jerry can holder. Fill what you need when you need it. You can remove them to lift it off the ball when solo.
Speski OffRoad LTD, Cargo Solutions for Toyota 4x4's http://www.SpeskiOffRoad.com
"80 series, with a fridge"
1976 FJ40, Project with little progress.
2004 Starcraft 10RT