14" Disk brakes

You can do the big pattern disc brake swap using '73 and later A/E parts (and arguably FMJ spindles), and just use the factory 10.87" rotors without up sizing to the 11 3/4" rotors, and keep the 14" wheels, if my memory is correct. It'll stop just fine that way.

I would DEFINITELY recommend trying it with a manual master cylinder before adding power brakes. You might be perfectly happy with it with just disc brakes alone.