I saw the Zalman ZM80D-HP was highly recommend here as silent GPU cooler, but then found some sites that say "This product is not installable on an nVidia GeForce 6800 GT, 6800 Ultra because they do not have 3mm holes around the GPU."
Doh

The rest of my PC is:
P180 case
Asus A8N-SLI Premium nForce4 SLI
Athlon 64 X2 4400
Scythe SCNJ-1000 Ninja with Nexus Fan
74gb Western Digital Raptor WD740
300gb Seagate Barracuda 7200.8
Seasonic S12 500W Power Supply
By far most of the noise is coming from the video card, the rest is actually surprisingly quiet.
Thanks!!