I have the same problem so I ended up Flat Towing my modified TJ. Even with an aluminum car hauler your going to be over 5000.
My buddy upgraded his hitch and had the frame reinforced to theoretically 10,000lbs, that being just a guesstimate. So he is at about 5700 lbs which is the Jeep (TJ) and aluminum trailer. He has a 29' with a A-class ford f-53 Chassis so there is not very much extension off the original frame, which helps. Look's solid to me.