Years on, but adding to this body of knowledge. I have an Australia Jeep KK (Cherokee) Limited. I have currently ran Cooper Discoverer H/T Plus M/S 255/55R18 for the last 40000km with no issues or rubbing on stock 18" rims and ride height. Very good road tire, quiet and loads of cornering grip. Nice off-road tire in rock, gravel, dirt, but my lack of dropping tire pressure and the stock low slung ride got me stuck to the frame in sand
I recently bought a 4x4 offroad camper trailer that weighs ~1000kg and it tows very nicely behind. BUT with the added trailer tongue weight, rooftop rack and frid in the back I've noticed I can't stand on the rear tires because of the sag! (without the trailer on my boots comfortably fit on top of the tires to load the rooftop Rola rack).
So I came across this post looking for what tires and sizes I could fit if I beef up the suspension and most likely lift the KK a tad, with heavier constant load springs in back and possibly air bag set up.
Will troll the site a bit more and pick up tidbits, but if anyone has done this and wants to share stories, please do!
jeff - aka CaptStarboard