I don't think there is any need to reinvent the wheel when it comes to PS's unless you need something super small and or want to build one yourself. You can get this (Logisys Corp. 480W 240-Pin Dual Fan 20+4 ATX Power Supply PS480D2) at Amazon for $18.54 USD and it supplies 16A on the +12V rail. And if you are an Amazon Prime member the shipping is 2-day free. Can't beat that.