The units that are available now are nice, most have a built in jack system for raising the car body to the rotation height. Expect to spend at least $1,000 for a decent one but you could recoup some of the cost if you sold it after the restoration is complete. I highly recommend a rotisserie for ease of work and better quality results on the restoration. I built my own rotisserie back in the early 80’s before they were available commercially, it was not fancy but it was strong and safe to use. I used front spindles from an AMC at each end so the car was resting on tapered roller bearings, it turned very easy. For wheels I used castors from scaffolding, they had brakes and poly wheels.
Jim