Well, there is nothing really wrong with any of these models. I would stay away from the Tahoes/Chevies if you want to go 4wheeling much in them. A Cherokee is a good wheeler, although it is a unibody rig (no frame, the body IS the frame), the Cherokee does lack front axle strength, but if you keep an open front axle and tires smaller than 35" tall you can run the stock front axle with lower gears.
A Toyota would be great! A truck or 4runner would be nice. Try to stay away from the 3VZE (3.0 V6), because it does not like head gaskets or valve cover gaskets. The 22re (4cyl) is a great motor, and only has about 5 horsepower less, plus better gas mileage (I'm not sure how high gas prices are in Mexico, so this may be a big deal, or not so bad).
In my opinion, if you want to seat 5, get a 4runner, unless you really like the Cherokee (XJ). If you don't need the 5 seats, get a Toyota pickup with the 4cyl. You won't regret it.
