This is 3 years old but I am wondering if we ever got a polishing motor in the end?
They would be great to use for a range of materials like metals, wood, epoxy or acrylic.
Dust collection can be done buy building and enclosure and could In theory have the shopvac attached. But generally there isn’t as much airborne dust for metal polishing because of the use of compound. Can not speak for wood or acrylic though.