Rear change for BBP - What would you do?

I have just acquired a 72 Dart, 318, 904, 7 1/4 rear car that I am going to use as my daily driver. It will never be a hot rod, just a classic driver. It has front drum brakes and the SBP. I want front disk brakes (for obvious reasons) and the BBP for more choices in wheels for the car. I can take care of the front but not sure what to do about the back.

A-Body 8 3/4s are expensive and would require an axle purchase. I currently have a B-body rear and axles so that could be an option. As I figure that woudl require moving in the perches and a deeper wheel backspace.

I was also thinking of finding an 8 1/4 from a 73-76 A-body as well.

So, what would you do? Any options I am not thingking about? Like I said, this will be a daily driver only and I am more concerned with smooth and low RPMs than hole shots and ETs.

Thanks,