Yeah, that would be hard to do with the original Kelsey Hayes SBP disks. At the moment most of those parts are available like that, but that hasn't always been true and more than likely it won't be the case going forward. The 73+ disks and BBP stuff is available like that, and you already have the most expensive part to do that, the 73+ large ball joint UCA's.
But even if you ordered the 73+ rotors from Doctor Diff with the 5x4" bolt pattern installed you would be able to order all the wearing parts other than the rotors themselves from your regular parts sources. And a set of rotors should last you close to 100k miles with normal use. Driving my '72 Challenger daily I put 70k miles on it, I swapped the pads out at around 50k miles but the rotors were fine for another go, and that was hauling in 275/40/17 front tires the whole time.