Just to keep yall informed - the shape of the top of the MJ Comanche cab and the shape of the top of the XJ Cherokee roof-lines DO NOT match up easily, and much fabrication and patchwork time will be spent there. Believe me, I wanted to build one with my MJ, but decided it was best to not cut up my really clean truck just for a tiny XJ back seat and have to shorten the bed or live with a ridiculously long but narrow vehicle. The proportions wouldn't be right unless it was lifted and sat on tires on the order of 37's. It just looks goofy near stock ride height or slightly lifted. The 2dr XJ mini truck(red one, first page of thread) is one of my favorite custom XJs.
And too bad there were no factory 4dr J-trucks, or an Eagle El-Camino.