Is there such a thing as a tabletop conche?
Stone based electrical wet grinders (not to confused with "wet/dry grinders", which are a type of blender), as are used in indian cuisine, have been used/modified by some chocolate enthusiasts as conches, and there are now some models by the same maker specially targeted for such usage, for example the Santha Spectra 11 model. Some models of unmodified stone grinders might be insufficient for that purpose due to restrictions on duty cycle (time the device can be kept running without overheating).