If you're considering a jeep platform "other" than a wrangler model, they aren't all towable 4 down ... Beware! Only the two speed transfer case is ( active drive II , I believe). This includes Cherokee and Grand Cherokee. Look at the shift lever, next to it on the consol should be a small button ( neutral). That's a sign you have the right transmission.
The new Renegade, Patriot, Compass, to the best of my knowledge aren't towable "4 down".
Good luck asking your salesperson, get a brochure and research what model you want on-line to be towed 4 down.