KH brakes questions

I have 71 Duster 340 drums all around. I have a KH disc brake set up that needs redone.
First question, will 15" Cragar S/S fit on them?
Second, How would I go about getting my disc set up redone? I doubt I can go to my local Napa and order them.
What needs to be redone? That's the first question.
Bleeding? New Pads? Check the rotors?
At the moment, new replacement parts for these are not a problem - with a few exceptions.