... and it's time to build a new system. So here's a stereotypical 'what should i get' thread. I haven't had much time to research all the hardware so I'm not exactly sure what is the latest and greatest. It'll be a desktop and I won't be moving it around much so size/weight isn't an issue. Cost isn't too important either but I don't want to spend like $500 on a case. I'm looking at:

case: antec p182 (http://www.antec.com/us/productDetails.php?ProdID=81820)
psu: truepower quattro (http://www.antec.com/us/productDetails.php?ProdID=27850)
cpu: intel core2 quad x6600 (http://www.newegg.com/Product/Product.aspx?Item=N82E16819115017)
vid card: ati 2900 HD (http://ati.amd.com/products/Radeonhd2900/specs.html)
sound card: creative x-fi

What motherboard? Which x-fi sound card? What RAM?
Aside from drives am I missing anything else?

Thoughts? Recommendations?