The problem I'm trying to solve is this: I'd like to be able to fly a Steadicam Merlin and adjust focus at the same time, perhaps with a remote control attached to the handle of the Merlin. The unit would have to be small, and pulling focus would have to be fairly straightforward (perhaps with a wheel). Can't really mount any gears on the lens, for weight and balance reasons; and want to be able to do it solo instead of with someone else pulling focus.

I can see several options when I enter these search terms into Google or B&H (Manfrotto and Okii,, for instance, make units that plug into the USB port), but I was wondering if anyone had any particular recommendations for what I'm looking for.

(Incidentally, the Moza gimbal also seems to have this functionality.)

Thanks for your help!

Would the DSLR Controller work?
Very simple to make wireless.