If you redrill the axles just have the new drums redrilled also. If you go to an aftermarket axle (Yukons are the cheapest) then you will just use any 8 1/4, 9 1/4, 7 1/4 or 8 3/4" 4.5" brake hardware. Yukon A-body replacement axles have the flange offset the same as the "regular" rears.
Yes...