wheel offset advice, camaro clip & diff

[atotalnincompoop]

i have installed an '80 camaro clip and diff in my airbagged 55 gmc. i plan on running gunmetal torque thrust wheels in the 20"-22" range.
just curious as to the wheel width and offset as well as the tire sizes that you guys have used. i'd like as big a tire as i can get while still having the full range of steering, if possible.
heres a pic before the snow hit...