ASUS's "DIRECT CU II" aftermarket cooling solutions are excellent, and very quiet.
MSI's "Twin Frozr" are also an excellent choice for an aftermarket cooled card.
Just up to you which one you choose to go with. Personally I was never that big on quiet video cards. Chances are always good that your CPU cooler will be the dominant noise maker in your case. I can't hardly even hear my cards running. Besides, like what was added below me, you won't notice your card's fans unless they're spinning fast enough to blow papers off your desk.