Can I run a normal PC mobo with this power supply? My fear is that the cable from the 4+4 pin is too short. Thanks for the help! In general, it is possible to connect a normal mainboard to this power supply, if all the required connections can be reached, but it is not intended for such a usage scenario, because besides the connections themselves, an additional external power supply (up to 160W) is needed, which has to be purchased additionally

Anything that provides 12 volts at the output and sufficient current for the specific application. It is best to measure the maximum current consumption during operation and then evaluate a power supply unit.