Update:
- the AMD stockcooler is also pretty quiet (*)
- should've gotten the HD4870 1024MB, didn't notice it before but it is only slightly more expensive & prolly more future-proof/a better fit for high resolutions

(*)
Had to temporarely install a noisy Hitachi drive, so system is not yet as quiet as I want it to be. Sometime next week I'll install a Samsung (400GB) that should be much much quieter.

1gb HD 4870 is good for 1920x1200 and up, at 1680x1050 and lower there is no difference