What Master Cylinder for 4 wheel disk brakes?

I am a streeter
I like my 15/16 M/C with a booster off an early F-body. This combo has a nice progressive feel to it, and locks up nice when I stand on it, lol.
-----------------------
I run 235/60-14s on the front and 295/50-15s on the back
On the front are the KH 4-piston fixed calipers and
on the back are 10x2 drums with 7/8ths w/cs, so
this set-up requires NO additional proportioning.
I run 1.03 T-bars and a big swaybar on the front.
At the back are de-arched HD springs, with a second mainleaf installed. The car is lowered to 5.75" to the lowest part of the K-member.
This set-up has just the right amount of weight-transfer on hard braking, and those 295s out back, when working hard, are like dragging a puller-sled. This allows me to come into a corner, braking really hard, and still be able to steer around it. Whereas if the car still had the factory proportioning, she wouldda locked up, jumped the curb, and been in who-knows-what-kind of trouble. I have not, in 23 years, broke a period aluminum wheel.
Yes there are times (braking hard in turns) when I suspect the rear is a tad heavy, but, with the 295s back there, it is easy to modulate the pedal and avoid trouble.

If you have big and littles like I do, don't be afraid to make the back actually work, lol; just be sure to stop experimenting before the back locks up first!

BTW
I sure wouldn't throw away the Master for a leaking cover. Especially if you are running Dot-5/silicone, which will find every stinking place it can, to leak from. If the leaky lid is all that is wrong with it, I would just fix it.