KZ Sportsmen Classic Toy Hauler Specifications:
Model 16KTH
UVW 2,285lb
GVW 3,500lb
NCC 1,217lb this is the caring weight, which is every thing you add to the camper. EVERYTHING
A friend ad a KZ Sportsmen, not a toy hauler, just a TT, the unit was well built.
There are other light weight units out there, and you are correct the Jeep Liberty has a max tow of 5,000lb, how ever I would try to stay well under that, safety and economy reasons.
I did a cargo trailer 14X7 conversion, and as others have posted, it is very hard to keep the weight down
DW and I just purchased a Jayco Octane 161 toy hauler, the dry weight is about 3,800lb, very nice TT, but it would be to heavy for your Liberty.
Johnnie