If you are considering 15" Steelies.....
For my 68 GTS, he did 15X7 fronts and 15X8 rears (4.5 BS I think) for around a hundred a piece & prolly $20.00-ish shipping per wheel.
Since you are supplying the centers, I'd think it would be cheaper, but there will be 2 way shipping.
Can't hurt to ask? PM me if you'd like his contact info.
PK