In the Stenning system, the camera itself is tiny, about 1/2" diameter and 1-1/2" long. It is motorized focusing lens that makes the assembly large. I had purchased a used micro CCD camera off Ebay, just like the one used with the Stenning system, and it came from an Endoscopic medical application and had a fairly small manually adjustable focusing head on it. Maybe a smaller manual focus would work for you.
The Dimetrics and Arc Machines systems are excellent I know, and as with any of these things, very costly.