I am evaluating about having build a DAW by professionals that have solid audio knowledge.
I have found some competent adresses in the US (www.adkproaudio.com and www.sonicalabs.com come into mind) but what about vendors in the EU? Have tried googling but not much luck so far. Any hints are welcome.
I looked at them, but I'd prefer to ensemble it myself. Have a look at one configuration of a good DAW builder (the manufacturer of each component and the model) Build into an Antec case (they have two models specially designed for noise isolation, one being the Sonata), with added acoustic foam, rubber supports for fans, hard disk noise isolator cases, and a BIG fan for the CPU (the bigger, the lower speed needed to cool)
After that, tune up your windows installation (http://www.musicxp.net/) and you're done! You'll save some money ending with the same performance (if you build it with the SAME components, of course)
I'd suggest you a dual Windows XP installation, one being ONLY for audio, and the other for anything else (games, internet, office...) so you choose one at boot time.