I'm lukewarm on the WJ. It's a nice Jeep, and does what we ask of it, but....
The background I have is having owned 3 XJs, 2 ZJs, and 1 WJ.
So, rambling:
I do prefer my ZJ over my wife's WJ. Our WJ is a 2004 base model 4x4 Laredo. It has the same I-6 in it. I've had that engine in 4 of my 6 Jeeps and performance wise, it didn't significatly outperform my '96 ZJ when the ZJ was in it's prime.
If you had the ability, I would definatly go with the V8. My 94 ZJ had the 5.2 in it and it flat out smoked any other Jeep I owned with accelaration. I've never driven a WJ with the 8 cyl. From a fuel consumptin rate in the WJ we are getting about 15 or so on average for MPG. My ZJ is getting at least a full mile to mile and a half better per gallon.
At 135,000 miles on the WJ I have replaced the t-stat twice, the valve cover seal, the transmission seal and it still needs an oil pan seal and a rear main seal. I have also had it in 2x to repair cut wires in the driver's side door crease and the driver's side power door latch is inoperable. As well, the fuel pump is failing which requires a tank drop to replace it.
From an ergonomic standpoint, I think the ZJ seats are a little more comfortable. I'm not a huge fan of the center stack lay out on the WJ. It is not as comfortable to reach to the radio for changing stations. Perhaps that would be a mute point if I had the steering wheel controls.
Regarding towing, I would advise against it. I believe that the I-6 vehicles are rated for about 5,000 lbs. Assuming an XJ for the trail is dressed at 4,000 (at least mine is) and the trailer is another 1,000 you are right on top of, or over, that tow rating. If you do want to trailer, find one with a factory hitch set up. If you go aftermarket you either need to notch or buy a brand new bumper cover or mount the hitch below the cover which will decrease your rear clearance.
Final think I don't like about the WJs is that the only place you can open the car with a key is the driver's door. Not lock on the tailgate or the passenger's door. I don't have room to carry 3 fobs, so I unlock all my Jeeps with the key. Not having 3 options to unlock is a pain in the ass.
My wife would like to trade up to a vehicle with a 3rd row, and she wants to turn in the ZJ and keep the WJ. I'm against that.
All that said, I would consider another WJ, but it would have to be significantly upgraded from base model.