Used a 12v brick from radioshack in series with a pot. Originally it was going to be used for powering 2 80mm fans. Think the max amperage it could put out was like 1A. Course thats passive now so all that thing is doing is powering an LED in the power switch
Im sure you could find a 5v brick that can give 1-2As just as easily. Just put them on 5v from a PSU and make sure they move enough air.