It has a cooler built into the radiator, but you could add an auxiliary cooler in front of the radiator/condenser if you want. The towing capacity of the Sportage is pretty low, though, so I don't think an add-on cooler is needed. Its not like your pulling a 10k lb boat up a mountain, unless you are, in which case I wouldn't admit it.
If your towing add a cooler. Towing is hard on any transmission. If you want to have a transmission in a cooler area get one that has the bypass valve. The bypass valve will not open in colder weather until your Tranny fluid is warmed up. If you just go and put a big tranny cooler on you will find you tranny will have a hard time changing gears in the cold. You could always change to synthetic Tranny fluid also.