Wheel and tires fitment for a 72 Nova?

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I have recently bought a 72 nova street/strip car from a friend, it has stock wheel tubs with trimmed fender lips in the rear, and a cpp basic rear disc conversion on a 12 bolt rear with c-clip eliminators. On the front, there are heidts tubular a arms, and a cpp basic disc brake kit as well.
What I am curious about is, what can I cram under it and make it a fun driver that might see a track day or two? I really would like to lower the car up to 3" and was thinking 17" or 18" wheels. I am on a pretty tight budget and have been looking at cheap aftermarket BMW wheels, but I really am lost on what sizes I can get away with, would a 275 40 18 on a 9.5 wheel fit the rear? How about a 255 on a 8.5 wheel on the front? I am open to suggestions on size, back spacing, and style. I am also looking for a wheel with a polished lip/shell and a painted or satin center. Any ideas on low budget solution? Best bang for the buck kinda stuff, I dont want to cheap out too much and sacrifice quallity and realibility. Thanks in advance.