The 2.5l in a TJ is not a very peppy engine in the first place. I've got one and have wheeled it stock and modified. I've towed over the 1000# rating with no problems. The biggest hurdle you will have either way is acceleration. I manually shift when I need to accelerate to gain speed to merge onto highway and traffic. Otherwise, it accelerates at its own speed....
If you plans to use this Jeep include the beaten paths some, I'd look into a teardrop style camper. You can buy a mfr'd one or build one yourself.
My camper that I put together used a pickup slide-in pop-up style box on a trailer frame I had put together. It worked for the short time period of thought to put something like this together, but in reality, it was a little short in a couple of ways that I didn't anticipate for its use.
The TJ, 4 or 6 cyl, is capable of towing upwards of 2000# if you are a safe, predictable driver. The short wheelbase of the TJ is what hinders the towing capacity to be greater. I would look into a small pop-up camper, something with a 8' box as this would give you queen bed on one end, double on the other (most of the time). There are even smaller base box pop-ups as well that are even lighter. Maximize your packing ability for your use and you shouldn't have any trouble with a properly mounted hitch frame on the TJ.
My TJ is mostly used for wheeling, but I've towed my camper to the trails, camped, and towed it back home. I do run with 35's and lockers in the axles along with lower gears to compensate for the 35s.
Why put yourself into a sardine can why it is really not necessary? How about looking at a pop-tent where it is another type of sardine can, but roomier....to atleast roll over in your bag.
