Well i use the ZALMAN VF1000 2 Ball VGA Cooler and it is just awesome. It's almost like it was passive cooling. It is not too expensive. Your problem is that you have a gtx so you need an extra ZM-RHS88 required only for 8800gts and gtx which makes the cooler price around 80.
::: Zalman, leading the world of Quiet Computing Solutions ::: you can read that in the FAQ section. Second I'm pretty convince the zalman takes way less room on the motherboard.
PLg