DoctorDiff has everything you need, including lines.
Master cylinder- Don't use the stock diameter, go 15/16". Better pedal feel, slightly longer pedal stroke, and a little easier on the leg. I prefer a manual set up with the 15/16" master over power brakes. I didn't like the plastic reservoir to start off with but no leaks and no corrosion is a big plus
Mopar Aluminum Master Cylinder Kit
Proportioning valve- this is a copy of the later prop valve. It'll bolt in place of the distribution block your car has now, and all the stock lines can be used. Unfortunately it looks like Cass is currently out of stock, but I'm sure he'll tell you how to get one or when he'll have them
Mopar 1 Piece Proportioning Valve
Line selector- walks you through everything you'll need to get your lines right
Mopar Front Brake Line Selector for A/B/E Body
And if you have any questions, Cass (doctordiff) can help!
The only other consideration is that since you're running 11" drums in the back, you might also want to upgrade to 11 3/4 disks up front. I'm assuming you already have 15" wheels. With a full 73+ conversion the only thing you'll need for this swap is the caliper brackets and rotors, both of which you can also get from DoctorDiff. If you stay with the standard 10.95" rotors you may need to add an adjustable prop valve into the rear line to back down the rear brakes, or consider changing out the wheel cylinder size. I think the standard ones are 15/16", but they also made a 7/8" if memory serves and that would dial them back a little.
