Which brakes ?

[Bernie]

This is a question that I posed on the 67-72 message board a few days ago. I didn't get much response, and it is pretty technical so I thought I'd try again here.
I have a 69 K20 and the axles off a 78 with discs in the front and a 14 bolt rear. I'm looking to buy a master cylinder, booster and proportioning valve. What set up do I need ? I know that one off a 71 would work with the push rod that I have (but I don't know if it's Delco or Bendix). On the other hand, which master is used on a 78 depends on the size of the rear brakes. I would be very grateful for the advice of anyone who has done this axle swap . Thanks