Many options. As post 2, any 67+ A, B, C, E body will be a 4 bolt dual MC that will work. The smaller the bore, the less pedal effort, but more travel. I recall 1" bore was standard in 1965 for power or manual, but rockauto shows all. But, sounds like you don't prefer rusty cast-iron w/ sheet-metal lids that often spill brake fluid (DOT 3,4 removes paint). With a 2 to 4 bolt adapter plate ($30 ebay), you can use later aluminum MC's. Many A-body guys use one for a 1980's Dodge truck. It has a plastic 2-cap reservoir. I have an MC for a 95-99 Breeze w/ ABS on my 1965 Newport's power booster, and works fine. I lucked into the booster on rockauto for $75 a few years ago, and sold the single-pot MC on it to a local guy, since I only run dual MC's. I use the distribution block for the fronts and attach a new tube from MC to rear tube. Autozone or ebay has the adapters you need (1/4 M inv flare to 3/16 F inv flare, 3/16 inv flare coupler, 3/16 plug).
Most newer MC's come w/ a low-level warning switch. You can use that if you wire in parallel w/ your e-brake handle switch (1-wire) w/ the other side wired to ground. Similarly, a proportioning valve imbalance switch can be wired to short the lamp to gnd. Thus, any of them can light the dash lamp. That is how newer cars are wired (my 96 Voyager). Best to avoid MC's newer than ~2000 when most switched to bubble-flare ports. You can form those w/ a standard dual-flare tool (youtube), though simpler to avoid them.
