Need Assists With New Gaming Rig

Hello,

I am new to the forums, but not to the site. I use to build pc's a lot back in 95 - 2000. But then started buying prebuilt machines since I didn't have time to understand the new technologies. But I am fed up with my machine at home. And wanted to get a new gaming rig.

What I want so far:

CPU: Q6600 (G0) http://www.newegg.com/Product/Product.aspx?Item=N82E168...

video card: ATI 4850 http://www.newegg.com/Product/Product.aspx?Item=N82E168...

CPU Fan: Artic 7 http://www.newegg.com/Product/Product.aspx?Item=N82E168...

case: XCLIO A380BK http://www.newegg.com/Product/Product.aspx?Item=N82E168...

What will I use it for:
Games (Specially UT3 w00t!!1)
Multimedia playback
TV once i get another hdtv.
Basic computer use (emails, internet, etc)
Small time video editing (basically putting videos on cd's w/menu options)

As mentioned gaming is the highest priority. And would like to play everything on max settings. Also have windows vista ultimate 64 bit, and would like to keep this maxed as well. Any suggestions to mobo, memory, and what I have so far I would greatly appreciate. Also, I do not want to change the Q6600 proccessor as 4 core will be the new wave. Anything else I don't care as long as the cost/performance ratio is worth it.