It might be over kill but I bought fans for RC cars that fit perfectly. The down side is you need to solder the plug. Also it sounds like a hair dryer is on. Cools the Argon ONE down very well. If you are going for quiet this may not be the option for you. 
2Pack RC Car Motor Cooling Fan Heatsink 28000RPM Brushless ESC Cooling Fan for RC Car 1/8 1/10 540 550 Motor (Black+Silver)
JST ZH 1.5MM 2 Pin Female (I did not need this many)