If you are up for Original ideas...
Ring & Pintle hitch. Military Surplus.
Cheap, indestructible, and will take anything you can throw at it off road.
For obvious reasons, you don't want your trailer any wider than your jeep.
You will want the trailer to be made of some pretty solid stuff...
So I suggest a military trailer, or something very close to a military trailer.
More... M416 Trailer Project
Once you have purchased or built something like this, make a heavy marine grade plywood top or metal top capable of supporting two people...
Instead of a 'Fold Out', you could use a regular 'off the shelf' tent on top.
This would get you up off the ground, give you a flat, stable platform and you would have tie down points for your tent no matter what terrain you were on.
You could camp on solid rock and you will still be able to set up a tent and be off the ground.
Another feature would be if you had a battery, an air compressor and an air mattress, you don't have to sleep on anything hard...
A pull out 'Foot Locker' at the tail gate keeps you from having to lift the top for camping stuff.
One of those 'I' beam based roller trays or heavy 'Glides' would give you access to nearly everything in the trailer even with the top closed.