I'm pretty much in the same boat with my needs... I want something than can push some screen real estate. I don't game. I don't overclock. And I want it to be quiet... My solution was 2x 6600 PCIe with passive cooling.
A couple of good points about that XFX card: 256MB, factory overclocked and SLI connector. The downside is the fan... I suspect with the GPU being overclocked it needed it.
For me the quietness was more important... I went with 2 of
these when woot had them on sale. The passive cooling mean ZERO noise. That was my biggest complaint about the XFX 6600GT I had (that fan LOOKS very familiar actually).
I went so far as to yesterday swap out the stock AMD HSF to a Zalman. 2nd one of those I've bought and love them. By comparison the PS2 (what I grab to play a game or 2) is LOUD compared to this PC and this thing has a X2 4400+, 2GB RAM, 4x WD Raptors in RAID5, 2 large PATA drives, and a DVD burner sitting in a Antec P180 with an Enermax EPS12V-650.