The internal PSU bit on the website was a mistake. It's since been corrected. It will be an external PSU.
So is this then going to be the same system as the current Singles, whereby there's a 12V power brick for every unit?
Is it going to use the exact same voltage and barrel connector size/type as the current Single also? I would very much like to hook up all the units to an ATX PSU - in fact I'd have done this already with parts supplied by Cablez if I knew said cables would be compatible with the new unit.