94 and 95 yj with the 4.0 have the ax15 with external slave for the clutch, much easier to fix on the trail.
It would depend on what you plan to do with your jeep when you get it and how far you plan to go on the modifications. heres a list to start out with.....
Windshield frame rust
Front floor board rust
Rust at fender and rocker flair attaching points
Rust at bumpstops, if they are still there!
Rust in frame at drivers side at the front of rear leafspring mounting points(by the fuel filter)
Rust in skid plate and skid plate mounting location to the frame.
Any oil leaks as they could be the most expensive to fix.
Check wiring harness for being hacked up, dry rotted and split wiring.
Check vacuum lines for dry rot and splitting.
Check drive shafts for slop in rear ends and u-joints also the slip yoke.
Make sure 4 wheel drive is operating properly.
Before purchase, drive it until it warms up properly. Make sure there are no popping, banging, clanking noises that don't belong!
I am sure I missed a few things others can add in. I have owned my 94 since 95 and it has been a continuing project since I purchased it. I off road any chance I get to.
If you can find one that has not been used off road alot that would be a good starting point. Jeeps have alot off aftermarket support and are easy to work on if you can't find the part you are looking for depending on your skill set you can probably make it!