The best advice site 1, best advice site 2 before you shop. I always go for silent PCs, I do not care for the money, I want my computer experience to be the best one there is. I do not mind if the CPU is not 20 C but 35 C as long as I and my hears can focus on the data of my work, and that data comes from the PC, so I have to be in it as much as possible when I'm working. Because the PC is not only your friend but your trap, and even traps should be silent to fall into. Of course the diziness in the brain after the hours of focused eyes on the screen cannot be avoided. The best drug is to have sex with your woman after a short cinema movie or something. This should not only relax you, but you will never lose touch with the social life that keeps you S A N E (as in scanners for linux, LOL).
PS. it shouldn't come as a surpise that the only fanboy letter that I ever wrote was about 2 years ago to ZALMAN for their 110€ (at that time) PSU. I mean I payed and I payed a lot and I got WHAT I WAS PROMISED (quality was not only there in Silence, but in cables, manual, etc). I don't hear A FUCKING THING. This is great (again not as great as when you come on a naked tit) but great enough :). have fun, keep SANE