Which ball joints to use?

[Maropesa]

I have a '65 3/4 ton which I want put disc brakes on. I have steering knuckles from a '73 and plan to buy calipers, rotors etc new. Will the new '65 ball joints work with the '73 spindles? One more question. When I did a search on the master cylinder I read that the master cylinder and booster from a '73 to '78 would work. Is this right? Is the porportioning valve built into these or do I have to add it?
Thanks for your help. I am new to this site and I think its great.