If you do let me know and I might have you build a second one for me on my LJ.
The good news: the fan I bought (which I think actually came out of a Thunderbird--it's the same fan/motor as the Taurus) has a squarish shroud which is the perfect size to install in a TJ. Seriously, all I had to do was attach a few angle brackets so I can bolt it into the OEM shroud bolt holes on the radiator itself.
The bad news: if you overheat on the highway, it is extremely unlikely to be the result of a faulty/weak fan. On the highway, you should have all the airflow you'd ever need to keep the coolant temp happy... unless you've blocked the radiator with a
huge winch and other accessories, or you have debris clogging up the radiator itself (such as between the condenser and the radiator), or any other scenario which prevents ambient air from flowing through the radiator core.
Do you run hot in town, too? Or just at freeway speeds?