If I was redesigning my braking system again I'd go with what Apogee mentioned, the smaller metric calipers....
Three reasons:
1- a Bronco doesn't need 1 ton braking capacity sized calipers...just doesn't
2- allows you to pick and choose amongst dozens of M/C applilcations...ones that are alum bodied and plastic reservoirs...no rust, they seal perfectly and are lighter
3- not important to 99% of Bronco owners but the smaller bracket gives you more room around the axle when designing 4 link systems, coill over/ORI mounts, etc.
I did forget to mention PhantomEB that you will need a brake bias valve to reduce the amount of pressure to the rear calipers. I have run a brake bias valve in the rear since close to '96. I'd never built a rig without that valve which allows you to absolutely dial in the brake bias...so important on such a short wheelbased rig
I have hydroboost with my setup and they work perfect...I mean they really are perfect... great pedal, great pedal "feel", stops on a flipping dime, I have the rear pressure reduced so they will just grab on gravel before the fronts... I like everything about the setup...EXCEPT the miserable leaking M/C. (it's cast and leaks).
I have run close to 8 different brake systems on this same Bronco since '76. Different axles, different calipers, combination disc/drum, etc... this ones the best.