Wheel spacers?

I am planning on leaving my car SBP and want Ralley wheels for it. This limits my choices. Today a friend told me they make SBP to LBP adaptors which add about 3/4" to the outboard offset. Has anyone here used these and if so does one need to buy deeper offset wheels to compensate for the added width. BTW, I am still in the market for a set of ralley wheels as the last deal fell through.
TIA, DM

I'm confused. Why not just buy a set of small bolt pattern rallyes, new or used? For the price of good, billet adapters, not to mention rallyes with a different offset, you could just buy a set of rallye wheels with either the large OR small bolt pattern...