To start up the PSU, I think you could do it more cheaply with a piece of wire, you just have to know which pins to short on the PSU 20 or 24 pin cable. Here's a wiki on it:
Some of you already know you don't have to have a constant circuit, just a quick contact and you're off and running. You could make a more permanent solution by scavenging a pc power switch.
tl;dr
Momentarily short the green wire with a black one to turn on the PSU