Master Cylinder Question

So, I have the AA swinging pedal/hydraulic clutch upgrade on my Jeep. One problem though, My new Dana 44 front axle has disc brakes and the AA master cylinder is incompatible with the disc brakes, AA says it's won't push enough fluid. I am planning on running two separate master cylinders, one for the clutch and one for the brakes. I would really like a brake master cylinder with front and rear outputs for redundancy. Here is my question: What size bore master cylinder do I want and why? There is one on ebay right now with a 1 1/8 inch bore that looks promising. Thanks in advance for you words of wisdom...

Mike