Looking for master cylinder suggestions on somewhat unique setup

Re OEM master cylinders, non-ABS can have ports for F & R on both sides, so you could plug the left side ports. As example, a 1999 Breeze/Sebring/Cirrus More Information for CARDONE 132731 ($35). But, bottom ports may fit your app better.

Until ~2000, U.S. cars mostly still used inverted-flare tube fittings. You can form later bubble-flares on 1/8" tubing using a dbl-flare tool (I have, see youtubes), but why fool with that? I used a Breeze ABS MC since only 2 ports (left side, so not for you). Why Breeze? I had grabbed an Intrepid booster w/ MC at the junkyard for my 65 Dart for its bolt pattern (slight rat-tail filing matched Dart brackets) but its slanted reservoir didn't work so swapped to a Breeze MC. Perhaps other MC's would work. As I stated, my 64 Valiant brake rod fit perfectly in the Breeze MC piston, though likely all 1990's MC's were for power brakes.

BTW, for those who want power brakes and a vacuum booster won't fit (headers), an alternative to hydro-boost (requires power steering) is the latest electric-boost MC's. I saw a youtube of a hobbyist displaying one from a Tesla. One son recently had a rental Honda CR-V so I peered under the hood. It appeared to also have an electric-boost brake MC, so likely many others do. Might need to wait a few years for more to crash so cheap at junkyards. For many years now, steering racks have had motorized assist built-in. I assume most/all are 12 VDC. Haven't seen a hobbyist use one, though might be easy if just 2 power wires to connect (no funky control box).