I got my master cylinder and prop valve from this guy, the ram man. He's very friendly and easy to talk to and will help you figure out how to set up your car. He's very knowledgeable and helpful. I've recommended him to others on the board here and they have pm'ed me back thanking me and stating that they enjoyed talking to him and learned alot from him.
He set me up with a dual reservoir master cylinder for my 66 Valiant wagon that I can use with my KH disc brake conversion.