A while back I posted an article on a new Media Centre PC that I built. Now with renovations getting to the AV install point there are some changes to some of the components. For one I need to change the TV card to a digital card and maybe add some noise dampening components. While I was looking around I came across this article on Audioholics.com about building a MCE PC. This has to be about the best article I've seen to date. Chris Tham whom I believe is Australian goes through the whole process step by step.
Check out the article if you are in the market to build one of these. It's a great resource even if you already have because you can benchmark your system against the recommendations in the article.
Mine is working great and its awesome to have this in the loungeroom as another AV device. Although soon its all going into a rack under our new stairwell so stay tuned for more details on that.
The good news is I've been able to find all the parts he mentions in the article through local online retailers.