Okay, my current plan is to use 5-core insulated cable and devise a keying system to prevent polarity reversal or worse. I plan to use colour coded wires, and to make connectors with male headers and heat shrink.
Kinda wondering now why I don’t just use 5 pin mini DIN. Whatever I end up with, it will be fantastic.
Edit: damn, this sounds so cool. Aviation connectors! The price is keen, too. Less than 50p each for a connector pair.
Edit 2: I misread the item text. You get 6 connector pairs, not 18. Still looks good to me.