Chnging bolt pattern on rear axles

I'm going to have the rear axles on my 8-3/4 diff. re-drilled to the larger 4-1/5" bolt pattern by Moser because I went with 15" front wheels for the Wilwood frt.disc conversion and want to put matching 15" Crager S/S on the rear when I install the new rear.

My question is: should I have them re-drill the brake drums 4-1/2" or go with brakes from a "B" body? Any other suggestions that don't involve big $$$

TIA,
65ChargerDart
Fortson, GA