What the other guys said is true. If you're really bold (fender flares and all) think about it this way. A seven inch wide rim with zero offset will have 3 1/2 (seven divided by two) inches of back spacing. This is what's required to keep the tires from rubbing any of the suspension parts.
Therefore, any wheel with 3 1/2 inch back spacing with the previously mentioned bolt pattern will do. The problem is that most wheels manufactured today fit today's modern suspensions. These require wheels with much greater back spacing and they won't fit our beloved cars. Our choices are limited.
I have 10 wide wheels with 3 1/2 inch back spacing on my GTO. I got them from VR Engineering, Tempe, AZ (480) 967-3289. Keep in mind, that these wheels change the suspension geometry. The "center of gravity" is no longer over the spindles. It's out, somewhere beyond the spindle. This will cause your bearings to wear differently. They should be checked regularly.
I hope this helps.
Lee