I would use both discs and master cylinder from the same donor car.

There is a relationship of master cylinder capacity/diameter for the calipers that you use.....and swapping over only one of those components
will cause problems.

Anything will fit anything, but sometimes you have to get creative and make your own brackets when you can't find a bolt-on swapover.

Best bet is to scrounge the junk yards and do some measuring there
to see what will fit. Carry in parts from your own car, if you have to.-Bob