If you're running on factory "premium" wheels, 285's is probably going to be your limit and whether or not you rub (and how bad) is really going to depend on what tire you get. (Stock Jeep with no lift looks really good with 285's...)
I ran 285's with aftermarket wheels that had 4" of backspace with zero issues. The stock wheels, you might need to adjust a steering stop a tiny bit, maybe trim some rubber to keep from hitting the swaybar, it's really hard to say. You may have no issues with your driving style.
Even running 35's with a 2/5" lift, I still hit the inner fender well when I turn to full lock to back out of a space.
I did a few trails with the 285's and stock suspension with zero issues, so wheeling shouldn't be a problem.
Be careful if you decide on spacers. Some places they're illegal, and as already stated, most shops won't work on a vehicle with spacers. All depends on where you are.
Make a man a fire and you keep him warm for a day....Set a man on fire and you keep him warm for the rest of his life....