I had a 97 Sport, 6 cyl. manual. Drove it for 9 years as my only vehicle, Put about 150k on it before getting rid of it, and I kick myself every day for not keeping it. The radiator went out at about 130k, and the exhaust manifold cracked somewhere around 100, both minor problems.
Also I didn't treat it the best. Got it when I was 20, and plowed through mud whenever I got the chance. I upgraded to Goodyear MTAs, expensive but awesome tires, great on the road too. Like esplanade, I rotated the hell out of them, and put lots of miles on them.
My biggest suggestion is GET FULL STEEL DOORS. That gives you a window you can roll down, and provides a much quieter ride than flapping plastic windows. Plus they're easy to take off before you leave the house if you want (two bolts on each). Also, if it's mainly a secondary vehicle or for your teenager, I wouldn't get about a hard top. The best part about having a jeep is riding with the top down. You can't just take the hard top on and off whenever and wherever you want. You're probably not driving it unless it's a nice day, and your kid can handle the noise, which really isn't that bad if you have the full doors. So get a soft top. You can also get a new aftermarket soft top that is thicker and quieter. See www.quadratec.com for everything Jeep. I remember being told by a mechanic that I trust that the 6 cyl was Just a better engine than the 4 cyl, so I would suggest a sport or Sahara for that purpose. Though that may or may not be a big deal.
I know it's difficult to find the perfect used car, but I would look for a 6 cyl with full steel doors, a soft top, and low mileage. I'd go manual, but that's just my jeep snobbery.