For the 73-73 a body sLBP discs You need to get the main swap parts from a donor car: spindle and caliper bracket. You can buy all the replacement parts from auto parts store. Pads, rotor caliper, caliper kits, hoses, bearings, seals, etc.
I typed aftermarket 14x6 rally wheel because that's what the aftermarket sells. They don't fit over factory SBP disc brakes.
Factory rally wheels are 14x5.5" and they fit over factory SBP disc brakes.