Hubert, this is where I got all my front disk conversion from.
https://www.getdiscbrakes.com/
You said something about using a proportioning valve along with what you have now..........DO NOT DO IT that way. As long as you have the right master cyl (a regular one for drum brakes wont work right)
you connect the valve like in my pic and get rid of the one down on the frame.
If you need stuff to get it done you can get pieces from the company above. A ton of people use "Right Stuff Detailing" parts and are satisfied.