My wife and I use a 95 Mitsubishi Montero SR for camping and getting back in the mountains. It has locking center and rear differentials and fits 33 inch tires with no modifications, which has gotten us out of some gnarly situations a few times. We also removed all the back seats and built a sleeping platform. It's the perfect vehicle for us, but probably too small inside if you're over 5'9". It can also be a little tricky to find parts. Honestly, the easiest trucks to find parts for will probably be the American makes and Toyota.
We use our 4 wheel drive often and rarely NEED the locking differentials, but when things get really rough they're a god-send. Our vehicle's basic 4wd mode is essentially all wheel drive, and it gets used pretty much any time we're off pavement. Most of the time this basic 4wd is plenty; having the ground clearance is actually probably more important for us. Grippy tires help significantly.
We also always carry an axe, water filter, a pretty thorough tool kit, water jugs, means for starting a fire easily, a first aid kit, some basic supplies like hoses, hose clamps, antifreeze, oil, gorilla tape, etc. One final piece of gear that we never leave home without if we're going into the mountains: our daypacks. If you break down and have to walk, it's really convenient to have a good backpack for carrying water and food.