If you are mechanically minded, then the YJ (to mid 97 Wrangler) was easier to work on (Less sensors and easy access to the fault codes) but it's leaf sprung and can be a bouncier ride than the TJ (Mid 97 on).
I have a TJ and it's in at the local Landy place to have some work done at the moment. It's all tried and tested mechanics on the wrangler, so you should be fairly safe.
Buy your parts from the US, and Servicing is not that expensive either. buy anything over here and it'll generally cost more (Few suppliers etc)
Had mine 3 or 4 years now.... Drum brakes on the rear stop working everytime it sees Mud (In having rear discs fitted as I type) but just need re-adjusting, replaced a few UJs and a couple of wheel bearings. Oh, and an exhaust because I backed it into a bank (Wish I could blame the car for that :) ). Being used in the mud it needs more TLC than one used on road. It's certainly never let me down so far.
And you can Mod it to your hearts content :)
EE