The 94 CAN be a good platform. The 96-98 V8 models make a little better starting point in my opinion, but it really depends on your plans for a build. For any amount of sustained wheeling of any difficulty, the 93-95 V8 models will need a rear axle swap and a t-case swap. The 35 is a ticking time bomb, and the early 249 cases leave a lot to be desired. They do not mechanically lock the front and rear driveshafts together in 4-Lo. This can become a problem on steep climbs as the front axle can lose power altogether. It is most common to swap in a Ford 8.8 rear axle from an Explorer or even the aluminum 44 out of 96-98 V8 models. For the t-case, a 231 or 242 out of pretty much any Jeep made between 1990 and 2005 will work. You also need to keep an eye on the front driveshaft as most of them are a CV style where all of the slip of the shaft is built in to the CV joint itself. They are very easy to blow up when the front swaybar is disco'd.
The 96-98 249 t-case does lock in 4-lo, and it does give you the stronger 44A rear axle. For a mild build, up to say 33's, they make a solid starting point. My wife bought a 98 V8 ZJ a little over 5 years ago and we put a 3.5" lift and 32's on it and it did VERY well.
Here's some pics of my wife's old ZJ (sold it last week) and mine:
More crawling than expedition, but this will give you an idea of what a ZJ can do:
I've been wheeling and building ZJ's for 10 years, they have their drawbacks, but can make a great rig. Lots of power available (factory V8), and a good amount of cargo room for hauling gear.
If I remember right you were on MallCrawlin a while back for a bit too, go check out some of the build threads there to see what ZJ's can be built to. Also look at any of the Grand Slam forums for trip reports on the various Grand Slams for a wide variety of built ZJ's, WJ's, and even some kickass WK's.
