Hi robin
The cercis controllers can operate two focusers from the one box and I think they are compatable with Robo focus units. I have one of these sitting around doing nothing so you are welcome to try it if you want. Looks like the pic on the page below but does not have all the DSLR stuff, that must be new. It is a focuser control unit only with two outputs and can be used for temp compensation if the sensors are plugged into it.
http://www.cercisastro.com/DslrStar.html
Cheers
Mark