IMHO it seems like your best course of action is to keep saving to do the BBP swap all around. Anything you put into cobbling the 8ΒΌ to handle SBP wheels is going to be trashed when you finally do the BBP swap.
I did the BBP swap one end at a time on the 73. I carried two spares which really cut into trunk space. What a PITA! Unless you can find a couple of nice BBP rallyes for the interim period your nice looking ride isn't going to look as nice.