33" is about as tall as you want to go on stock suspension. Once you get around the 11" wide mark, you need to start thinking about wheel spacers if you stay with stock wheels (which I definitely wouldn't) or new wheels with 4.5" of backspacing of less.
Tires for your stock 18" Sahara wheels are VERY expensive. I would highly recommend you purchase new wheels and tires. There are several options in the 15" diameter and even more in the 16". Of course, you have tons of options if you want to step up to 17" wheels, but the cost starts to become a factor again.
A very popular combo around here is 15" wheels (MB72s, Black Rock 909s, MB Chaos, etc) with 33x12.5x15 Duratracs. With this setup, you shouldn't have any rubbing issues on road, but you may get a bit of fender contact if you offroad and get flexy.
Another popular combo is a 16" wheel (Level 8 Trackers/ZX/Strike5, MB72s, etc) with a 285/75/16 tire. This measures out to around a 33x11 tire. I personally run the 16x8.5 Level 8 Strike 5 (4.5" backspace) wrapped in 285/75/16 Falken Rocky Mountain ATS.
If you step up to 17s, the options are almost endless. But, like I said, they don't come cheap and most setups in this range are quite heavy.
BTW, welcome to the forum.