[jhautz]

I didnt even notice they were 12v. I agree... look for somw 5v fans. The heat sinks on those would be prfect though. The Quark is 37mm X 74mm. 2 40X40 heatsinks will cover the entire back surface of the controller. The 5v fans metalman linked were perfect. I founs some on ebay, but they were more expensive than metalmans.

If you can, run fans. I like the insurance of a nice cool esc. I'm sure you would be fine w/ no fan if you can position it so you get some decent airflow over the heatsink.