I tend to use the Supermicro X7DAE in many many builds. It is solid, stable, and never has any issues. Also, I use the Titan 650 as well. Same thing: solid, simple, good cooling, and decently quiet. Now, the coolers on those Xeons are going to be loud no matter what. Yes, there is some BIOS speed control, but not much. I recently built a system for a client with some Thermalright Coolers. Please refer to this thread.
http://www.hardwarecanucks.com/forum...t-suckers.html
Oh, ECC is not too expensive. I would definitely go 4GB Minimum, as you usually want at least a gig per core.
KINGSTON 2XDDR2 2GB 667 ECC FULLY BUFFERED KVR667D2D4F5K2/4G at FrontierPC.com Canada