basicly a sport trac is a explorer with about 4 extra feet of frame.
the drive trains and engines are damn near if not exact matches to explorers of the same years.
As such they all have that odd leak between the tranny and engine.
mine has a small leak i cant seem to beat on the passenger front axle, theres a bit of moisture and despite replacing the seal 2x it still seeps, no drips just moisture.
check the rear power window for function, thay have alot of gremlins and arent exactly cheap to fix, its like 2 hours just to get to the motor iirc. then the motor is about 150$
the 4x4 is pretty solid, though mine has an issue of not going into 4 low lately, not sure whats up with that.
i own a 02 poineer edition (pioneer premium sound system and some other upgrades) with just over 91k on it so your 100k is still pretty damn low. But be ready to replace plugs, wires, pcv, fuel and air filters soon as you get it home. then changing the tranny fluid wouldnt be a bad idea either.
good luck, i love my trac and wouldnt trade it for anything, except maybe a newer model with a v8
if your gonna tow, get a newer model with a v8 you wont regret it. you could tow with the v6 but that depends on how big of a car. ive never towed anything but my dads 14' aluminum fishing boat which cant weigh nearly half as much as a car.