Wheel hub sources?

Your friend is making needless work and worry for you. Unless a bearing race spun, the hub should be re-usable. It is rugged forged steel. Anything new that isn't "old stock" could be inferior metal.

The only way I know to get new hubs is with the 1973+ front disk brakes, since the rotor and hub is integral, or after-market disk setups like Wilwood. The former also requires changing the spindle, both ball joints and upper control arm, so not trivial.

Unlikely your drums haven't already been changed once. If so, the swedge is already gone. I have removed drums by throwing them down (on inside edge) in a (vacant) parking lot until the hub falls out.

There is no hub in the rear. The wheel bolts to the "axle". It is possible to pull out the whole axle and replace the seal, but that requires cutting off and pressing on a new tapered roller bearing (or newer Green bearing), so a shop job.