8 3/4 build

So I picked up an A Body 8 3/4 for 100. As you probably have guessed it’s a empty housing. My 67 Dart has its original 7 1/4 that it stayed life with.

I think I can find a b body center section relatively cheap locally. I planned to do 3.73/3.91 gears and Eaton Truetrac.

My question is about the axle shafts and brakes. First can I/ should I reuse the stock brakes from my 7 1/4? Or should I just do a disc swap.
Second I want to get something like Mosier, Yukon or Dutchman axles. I’d rather run taper bearing than green bearings and I’d like to not have to cut them. Any opinions on those three companies or is there a better option? I’d also like to do the big bolt pattern swap while I’m at it.