Its not a standard size 2 pin fan plug, its slightly bigger so I don't think it will be easy to find the exact plug needed. Actually, a standard molex will fit if you are careful, at the cost of the FAN1 header (since the molex will block it). Just make sure you get it the right way around (You want the black/earth wire nearest FAN1). Sure its not the neatest solution, but its the easiest!
