forgive me if someone already said this, im kinda in a rush and didnt read all of the posts but here goes....
a pc power supply wont work for the pelt, regardless if it says that it puts out 25 amps because its divided amongst the different voltages leads and they generally rate it peak power not nominal power. i ran my 266 watt pelt on a 400 watt atx psu and it would only give me 11.95 volts @ 16-18 amps nothing more. I use the meanwell S-320-12 which is adjustable from i think 9volts up to 15.5 volts and im running right around 13volts. That power supply you SHOULD be able to find for 80 bucks if you take some time to look around
i got mine for 80 on the button including shipping (70 and 10 for shipping)
good luck
Steve-O