a yj is gonna be perfect for ya. like already said 91-95, and i'd suggest skipping the 4 bangers and go right to 4.0. some people think they'll switch it out later, which is fine, but it is more work and money than buying the six right away, its a great motor, and plenty of power.
floorboards for rust
rocker panels inside for rust
windshield frame for rust-easily replacable, but costs money
frame for rot, especially rear of frame
diamond plate hides sins
4x4 working, usually easy fix if it isn't
make sure tailgate isn't falling off
check hard tops for cracks and lift gate operation, and check soft tops for rips, and how the zippers and bars are working
finding one unmolested is best, people do weird things to jeeps. yj's with body lifts are gonna have weaker tubs usually with age.
you're price range is perfect to find a yj in good shape, enjoy.