Whenever buying a vehicle, one must stop and think of what exactly is the purpose of the car. If it is to look pretty and get chicks then a sports car, or these days a tricked out honda, might be your thing. If you want a spirited drive with tight cornering a mazda miata is a FINE car. But old Bertha here is to haul... stuff; so there are 2 requirements to a tow vehicle:
1. drivetrain. gotta have 4wd and an ironclad automatic is helpful. I love a stick, but I like to be able to ease into the power without having to concentrate on both engine rpm AND whether the tires are about to slip.
2. weight. steel is your friend, and you want a nice chassis. screw the body, you're not picking up chicks in this thing anyway.
Who cares about handling? Brakes are important, yeah, but this thing isn't an autocross machine. A buddy of mine with a miata invited me up to this miata car club get together where they drive through this really curvy road in the mountains. A lot of fun I'm sure, but a deathtrap for a steel brick. My buddy laughed and laughed at the ancient suspension (look it up, a model T has a more advanced front suspension geometry) and the weight. The fact that the 3/4 ton back suspension means my back tires bounce into the air if I hit a speedbump at more than 5mph sure isn't helping much either. I work for uhaul and believe me, even our old stickshift diesels ride better. I told my buddy that I'd be glad to go to this curvy road (the Gap or the Dragon they call it) if he could pull a 6 ton box truck up a 30 degree incline on wet pavement. He asked why he'd want to do that. I asked why he'd want to drive down a curvy road.
As for the transmission, originally it had a Turbo 350 transmission bolted to a NP203 transfer case. I've swapped out for a 1992 700R4, and that (combined with the fuel injection) nets me about 14mpg. It'll be a while before I swap out that NP203 though. Telling people I don't have 2wd is still pretty funny. The NP203 is full time four wheel drive and about the only options it has are high(1:1), low (1.98:1), and a locker for both. But on the other hand it weighs almost 300lbs and is made of IRON and STEEL.
Others say a big engine is vitally important to a good tow vehicle and yeah I guess it is, but who cares if your transmission self destructs or you can't put that power to the ground? On to the second page to discuss the powerplant.