got a junkyard? I'd go pull a rotor from a truck with the same bolt pattern, pretty much any F-150 from mid 70s to mid 90s. Measure the spindle length, buy the rotor and bearings. Now go home and pull your drum/hub and start measuring. Inner and outer diameter for bearings and seals. Take those dimensions to any good bearing shop and they will fix you up.Depending on the spindle length, you may need a spacer made.
Remove the backing plate. At this point I usually use the cheap weld on brackets from Speedway or summit and modify them to bolt to the spindle. You will need to add some material. You can get them for the big chevy calipers or the metric ones. You'd probably want the larger. Also from Speedway you can get the hose kit. Using this method and used rotors, I have done disc brakes for way under $200. I have never bought a kit .