As far as design goes I already have a lot on my plate both at work, and at home. What sort of assembly volume would we be talking about? I don't know if it would fit into this community, but I am working on a new breed of 3d printer controller that instead of a micro talking to the GUI computer or an sd card. I am writing an Real-Time computing controller that runs as a process in the background of windows. talking to the Printer GUI with a virtual serial. This RT-controller runs MEI cards which go to a digital break out as well as motor amp cards for the steppers, which also take linear hall effect sensors, giving lightening speed and precision.