I have the pins and crimper on hand from 3D printing hobby, but my preference would be Molex Microfit.
Real Molex ones can be expensive, but knock offs are available cheap.
If you'd rather splice wires than crimp you could get a 24 pin ATX power supply extension cable and cut it in the middle, leaving you with a male and female connector with wires coming off of them.
Probably the cheaper route if you don't already have the proper crimper.
Edit: I will add that the big downside to the micro-fit is that the pins are almost impossible to remove without special tools so if you need to redo one pin it is a PITA.