So I just tried it with a very nice cheap 1920x1080 camera from Amazon, sensor is perfect for our use, easy to rip apart and about 6mm of vertical resolution. However there is a problem, the library I'm using to connect to the camera only supports YUV format, which is a raw uncompressed image format. This means that over the USB connection higher def cameras cannot deliver the full frame rate of the camera because there is too much data to ship, I can only get 5 fps.

I will have a look about for a different library, this would use MJPEG to compress the frames on the camera so they fit down the USB connection, that may in turn lead to other problems due to compression artifacts reducing the image accuracy, will have to see.