I'd get set of ET Team III Vintage wheels in 15 x 8 with a back space of 5". Then get a set of 255/60 r 15 Cooper Cobra tires and have Diamond back remove all the side wall print. They will look vintage.
Besides you will need to install modern front upper and lower control arms with tall ball joints to remove the reverse camber during jounce condition that all GM A bodys had...
http://www.etmags.com/classic_v.html