Front wheels/tires: Cragar 61G 15x8 w/ 4.25 BS wrapped in BFG Radial T/A's 225/70R15
Rear wheels/tires: Cragar 61G 15x8 w/ 5.0 BS wrapped in BFG Radial T/A's 275/60R15
Cragar will make any custom backspace you want for $20 a wheel (2 piece wheel). The rear 5" BS was perfectly centered (bout 1" clearance on both sides) in the wheel well for the 275 rears and filled them up nicely.
One thing i learned is that the wider the tire goes the taller it gets which is why we went with the 70 series fronts. We initially had 60 series fronts but it looked to out of place since they were almost 2" smaller in diameter than the rears. The car is lowered 1" all the way around.