I generally use the factory pin type calipers, 70-74 E body/70-2 B body, as I prefer those for there fluid displacement to match them to the Stainless Steel Brake Corp (SSBC) Dana/8 3/4" rear disc package on my cars, as well as customers cars,...I'd recommend a 1 " bore master cylinder (power or manual) the SSBC rears will allow you to retain the factory parking brake cables without mods,...you can ditch the proportioning valve,...just Tee off the front lines, the rear line can come directly off the master,....when installing the rear kit, it is supplied with a spacer to replace the rear drum brake backing plate, so you won't have problems with the rear axle carrier, unlike some other kits on the market,...just be sure to use the shims (washers supplied) to center the loaded caliper over the rotor, so that the pads are displaced equally,...something the instructions don't mention at all, usually a no brainer, but some people goof this area, and burn up rotor or pads because the caliper is not centered on the rotor,...up front run either the A body, or F/J or 73 later B body spindle so that you can utilize the later 1 pc unicast factory rotors,...I generally use the earlier pin style caliper bracket, as it bolts on to the later spindles,...unless you prefer floaters (Calipers),...I recommend Stainless steel brake lines (tubing) seeing your doing the system over, do it once, do it right, never touch it again
Mike