Depends on the length of the replacement arms (if they're even included)...
If they're longer than stock, you MAY be able to fit 32's with a different front bumper. You'll also have to address the rear. Bumpstops are a must for both. I'd say you can expect to need 1.5 - 2 inches of extension for your bumpstops to keep you from stuffing your tire into your fenderwell. I've trimmed my front bumper from the bottom line down, and have ALMOST no rubbing. In the rear, when I flex the ZJ out, I get some rubbing on my rear bumper, but hey its plastic.
IMHO if you're uhhh.. hesitant to cut, go with 31's. Also keep in mind that if you don't want to rub your tire on the LCAs at full turn, you'll need some new rims with more backspacing. Stock rims will work, but you'll lose some turning radius.
HTH
Hank[/i]