G day donuts.
My work vehicle is a V8 TD Work mate. It has 16 inch steel rims fitted and we use the standard 265 70 R16 tyres size. These are cheaper and available just about any where. Our ute is fitted permanently with an Obieco service body (same as telstra) and has two spares on the rear. We rotate through the 6 tyres and don't replace them before the vehicle is traded in at about 80k.
Ours has a 2inch 3700kg GVM upgrade under it. The thing goes every where, probably places that fully pimped versions never would. This one is owned by the Govt, is used for patrol work by various individuals, who are hard on vehicles.
I have found no limitations with the standard set up, if its aesthetics your after then that is a different storey. As it would definitely look better with bigger rubber.
Regards
jas