They look pretty similar to the ones I got today, mine are domino 5 pin but I'll only be using four. They aren't locking either like the ones in your link but are a pretty good fit and connection. I've gone for 4 plugs and sockets at the moment as you've suggested to keep the limits etc on a separate plug. Next question is what cable to use? I had some instrument cable that has four cores and is screened but my mind played tricks on me as I thought they had about 1mm core but alas it's only about 0.2 mm So not much good for 5 amps. The motor peak current is 4.2 A so I'm expecting anything above about 1 mm would be sufficient and not give me too much volt drop over the 4 to 5 meter run (preferably screened). how important do you think the screening is? The most crucial part of the screening I would have thought is in the step pulses to the driver as any parasitic elements on this line could distort the wave form but these are a good distance from any motors (noise sources) and very short so I'm not expecting problems there.