I like an 8" wide rim that width of tire for off-road use. It protects the lip of the wheel better from getting dinged up, helps keep mud/sticks/rocks out of the bead of the tire, and helps keep the tires seated at lower pressures. Several guys in our club, including myself, are running 8" rims with 15.5 wide tires with very good success.
Getting off topic some, but I just have to comment about the whole idea of only running 2wd or keeping the front axle unlocked. I completely disagree with these thoughts as I have personally seen more people break components doing these things (2wd or keeping the front unlocked if a selectrable locker) in an attempt to keep the front axle alive. You have to beat on the truck so much harder to get through an obstacle that you put a lot of stress on the other components. I can't count the number of times I have seen people break the front ends and while trying to get off the trail in 2wd they wind up breaking the rear driveshaft or rear axle, and I have also seen people with front selectable lockers keep them off to try to save the front end and wind up still breaking something in the front axle because of instead of crawling it they have to hit it a lot harder.
If you wait until you are stuck to put it in 4wd or lock the front locker, often times it's too late and your stuck because you have lost your momentum. And if you do get in a situation where you break the front axle because of the locker, than most likely you wouldn't be able to make it without it.