Welp, keyword is quiet... so I'll post my input here.
Depending on how powerful the video card is, you can get a passive-cooled heatsink that is completely quiet. On the other hand, you may need something with a bit more kick. My R9800Pro has a
Zalman VF700-Cu cooler. I personally like this cooler a lot. But there is catch to that. The heatsink seems to occupy a little too much space and you may end up not being able to use Crossfire on your system. If you intend to keep a single-card solution in the long run, this is a good quiet VGA cooler to get. As Teck mentioned, there are others to choose from. But Zalman is definitely a good contender for quiet coolers.