Well, if that's a nice shotgun splatter on the barn wall kind of truck list if ever I have seen one. Surprised you don't have an idea of where to head at for your goals.
Goals, think about these first. Do you need a back seat for people hauling or not? Do you want to always have your gear with you at all times or would a trailer to base camp out of work? Do you need a pickup for utility hauling or not?
Lots of examples kicked out so this will add to the list a couple of things not already put out there. Plus, my favorites of the existing ideas so far are a 70's or 80's ford Bronco, expecially the 70's since these were not cluttered up with the modern things that complicate the mechanicals and electricals.
1. Your Rubicon is the best out-of-the-box offroader in North America, at least until you get way high in $$$ such as a Defender. Your best bet I believe is to keep the Jeep and get a trailer. You can save $$$ on this by getting a military surplus trailer to haul your camping gear and thus lighten up the truck.
2. Probably the best Nissan truck available in North America for offroading was the 1990's WD21 Pathfinder in the SE trim so you can have its real functional limited slip differential. You can do a poor man's suspension lift for a couple of hundred bucks by putting junk yard sourced F-100 or F-150 front coil springs in the rear matched with a crank on the front torsion bars to lift the front some then pay for the realignment that is necessary. For a few more $$$, a 2" body lift is not complicated. Now, you're setup for 33" tires and a strong little truck equipped with a very rugged VG30 V6.
Subsitute a W21 Hardbody for what I said about the Pathfinder above in all respects except it has rear leaf springs instead of coils.
3. Keep away from tires greater than 33 inches unless you go with a full size truck. They are going to kill MPG plus your going to get into mandiatory regearing of any midsize or small truck.
