I built this a while back, and finally got some pictures of it.
SPECS:
Opteron 144 1.8ghz (Thermalright SI-97a heatsink)
Asus A8N-E motherboard
1.28 GB PC3200 ram
ATI X300SE video card
80gb Seagate ST380011A (IDE)
160gb Western Digital WD1600JB-00REA0 (IDE)
The fan on the CPU heatsink is a Nexus 92mm, and while it is completely inaudible at 670 or so RPM, it leaves really no headroom for summer. I am looking into getting a triple blade low speed Delta for summer use.
The 80mm fan in the lower area is there to cool the Nforce 4 chipset. I couldn't stand the whiny litle fan, and this Yate Loon at 5v cools just as well, and it also adds some airflow to the memory and the vid card. In terms of noise level, it might as well not even be there.
The front fan (though you may not be able to see it) is a 120mm Yate Loon at 5v. It does its job admirably. The rear fan is a Cooler Master 120mm (it came with the case) at 5v. It makes a bit of bearing noise, and is scheduled to be replaced with a Yate Loon.
The hard drives are audible, and thats all there is too it. The tooless mounting system of the case allows them to rattle and it amplifies the seek noise (the WD especially) and short of suspending the drives, there really isn't anything I can do about it. It does not really bother me though. The whining of my DSL modem is louder than they are.
The PSU (Thermaltake 430w) is carried over from my first build and it is moderately noisy. I was considering replacing the fans with 80mm GlobalWin NCBs.