Above is our prototype, hand-soldered light circuit that served well, and stood up to abuse for a couple months. We’re now confident that the design is sound, so the next step was to design a production circuit board:

We’re sending this PCB layout out to get a prototype made. The board is 100% Arduino compatible, communication and power is supplied by USB, and the circuit allows fine-grained intensity/dimmer control for the high power Cree-LEDs.