You might ask the question at Anvilfire.com on the "Guru's Den" section. This has been discussed there, but I don't know if there was a supplier.

Hello monsoon12, do you have any access to a pattern burning table,or waterjet,or some other sort of programmable cutting unit? If not, simply having a circle cutter for a hand-held plasma or oxy-fuel cutting torch would probably do to cut some circles of the appropriate diameter. If you're trying to depress the center you might try finding a short length of pipe(the I.D. being slightly smaller than the diameter of the circle) and placing the circle over the end of the pipe and using a soft face or dead blow hammer to depress the center of the circle to make your wax retainer. You could also use the ball peen end of a hammer to give it some character. Then if you need something in the center to hold the candle, use a small diameter pipe of the correct size that fits the candle and weld it to the center of your circle.
      If you have ever watched someone use a leather bag filled with sand and a hammer with a rounded plastic end, form and round metal, that is along the same lines, I believe that method is used in many instances to work copper, brass, and aluminum. I don't know the appropriate name for this or the names of the tools, but I believe you can get the idea. Hope this somewhat covers what your question was. Regards, aevald