I had the same question when we bought our White hawk with the swivel entertainment center with the mirror on the back. I asked over and over what to use and never got a real answer. What I ended up doing was buying a normal flat panel T.V. mount from a department store. I threw out the lag screws that came with the mount and bought my own. I measured how thick the back panel of the swivel is (I think you can see the thickness if you swivel it sideways). I bought new lag screws the proper length so they wouldn't hit the mirror. I predrilled holes in the back panel of the swivel and attached the mount to the back panel using the new lag screws.
It is very solid and I have no concerns with its strength. I can't take pictures because she is put to bed for the winter. But basically it's like installing one at home but you use shorter screws and you don't need to find a stud.