I'm currently looking, with no real candidate in mind. My criteria are twofold: First, the camera needs to adjust over at least a 12" range, preferably 18", to allow for both Macro and Super Macro operation and to make room for axial lighting if I choose. Second, I want the smallest and most flexible lighting possible. I want to be able to bring both lights close enough to touch the camera, and far enough out to sidelight a coin from no more than 15 degrees above horizontal. That will give me the flexibility to get straight on to really lustrous coins, as well as sidelighting die cracks and errors which are my specialty.
It may be that I'm going to acquire the lighting separately from the camera mount. If required, I'll fabricate a stand for the whole thing.
A guy I saw on the NGC boards fabbed a camera mount from an old drill press. It was cool as all get out.