One of the brake upgrades for my car is a direct bolt-on replacement of the rotor, caliper, bracket, everything from the Mazda 6. Now, the question I haven't seen answered is whether or not a bigger master cylinder would be required, or at least if not required, if it would be a sensible upgrade. I'm not sure how the system works, but I'd think a bigger piston would require more brake fluid to be moved, and a bigger MC would be needed for that.
I looked on Rock Auto, and first is the picture of the one from the Mazda 6, which comes only with an ABS option.
Next is the one for my 626, manual, rear drum brakes, and no ABS
From my measurements, 15/16" is larger than 20mm, but the Push Rod Depth is larger on the 6's version, albeit it lacks the bottom port. They don't seem all that different, otherwise.
My other question is how long does it take for the motor mounts to dry after filling them with window caulk?