What Master Cylinder for 4 wheel disk brakes?

I have willwood discs in the front and foreign discs in rear (Ferd discs on 8.8 rear end). I currently have power brakes and my master cylinder is leaking from the cover. I want to replace it. I have a proportioning valve from a disc/drum car 73 Duster. And an adjustable proportioning valve.
I am also thinking of going manual. The car in question is 67 Barracuda originally manual drum