I know you said that you can't really be bothered to wire them up yourself but it should be a pretty simple to do. This may be your only option if you can't find a switch. I can think of an easy way to do it without acctualy having to crack open either of the PSU's. Why exactly do you need to run 2? One for computer and the other for casemods?
link the green wire to your switch and then to ground black wire but the power suply would turn off as soon as you press the button so it would be best to get a connecter
i dont think thats what hes after i think its a connecter so that when he turns on the computer both psu's start so that he can runn his harddrives and other stuff off one psu and motherbard and stuff of another