I did come across one cable in the Corsair pack which had eight connectors at either end labelled Type 3 at one end and CPU at the other. Someone showed me that the CPU end could be split into two four connectors and then one of those four could attach to the square socket on the motherboard. However I had no success getting the system to boot. Maybe I connected it wrong...
I'm tempted to get a different motherboard, but want to ensure that it will work withe this PSU. Is there a list of Mini ITX motherboards, preferably a few years old that I can buy knowing they should just work?