I converted mine.
I was lucky enough to find an old Tiger rearend that was already 5 lug for drag racing. It had hubs that looked similar and they appear to be made by a good machinist. I have also heard that Studebakers used Dana 44 rears with the same hub and they can be used. Also, old CJ5 Jeeps might work, but they use a bigger bolt pattern like Ford trucks. Doug Jennings has those blank hubs and they are $250 each.
For the front, old Mustangs, Mavericks, Granadas, etc uses the same outer bearing as a Sunbeam. But the inner bearing on a Sunbeam is smaller. Plus the Sunbeam has a very deep hub with that large hat that sits the wheels outward. So it was very easy to take dimensions off a Mustang and make a spacer that fits onto the Sunbeam spindle and accepts the Mustang inner bearing. Then you can use the Ford rotors but will have to convert the calipers to something that fits the wider caliper than the thin Sunbeam. I converted my car to Brembos from a Porsche.