I would say Min 350Watt
A 400Watt would be great
Hears a 500watt for 17 bucks
http://store.yahoo.com/akidacomputer/acpowsup50du.html
For plugs just buy some spliters.
ATX powersuppy is for all newer comps.
Older at power supplys have there own switch.
By the way the light is eather a cold Cathode or a neon.