Im assuming from your avatar that you have had a 2" lift? When i first lifted mine by that much i installed a set of 235/85/16, but to my cost i found that this was not such a great idea as they fouled pretty much everywhere, and therefore gave me the offroad ability of a mini!!
So the next step was to cut a few bits out here and there (Neils the man to talk about here as he has some good pics detailing what he removed) and this allowed me better axle articulation with these tyres, but as with all things SIZE DOES MATTER :D
I then went and got myself a set of arch extensions from Devon 4x4 and cut out about 3" of metalwork all around the arches, and installed them........but the 235/85/16 tyres then lookes too small for the now cavernous arches, so the next thing to do was to get myself a set of 265/75/16 grizzly claws, and this is where i am at now, and with the mods that i have done i get no fouling anywhere.
Costwise it all depends on how much you want to do yourself.
Oh yes i forgot, i did also have to reduce the steering lock a fair bit to stop the inside of the tyres rubbing on the steering!
So its up to you how far you want to go.