Media PC Comments please

Hi Guys,
New to the forums and just wanted a bit of a hand. Im going to be ordering and building a new Media center PC in the coming weeks and just thought i'd grab a few opinions before i committed. So heres the proposed specs, please let me know what you think or what i could change!
- SilverStone GD01MX Case Silver
- Antec Truepower2 480W PSU
- LG 18x SATA DVDRW
- GA-P35-DS3 Motherboard
- 320GB SATA HDD Seagate
- INTEL CORE 2 QUAD Q6600 2.4GHz/1066 FSB
- 2GB DDR2-800
- LEADTEK DTV2000H AN/DI PCI
- CREATIVE SB 5.1 Soundcard
- Windows Vista Home PREMIUM
- Logitech X-540 5.1 system
- MS DESKTOP 500 USB KB
- VIEWSONIC 28"VX2835WM W/S 3MS

I'm also interested in a videocard to do proper 1080p. Maybe even play a few games (I do mean few - im happy with my xbox). I was thinking that i might purchase an 8800GT in a few months time or something, however im not decided. If i do get a video card i do want to do it properly and get something that will do 1080p. On that note, the Monitor has an HDMI input so i would want to make use of that. Whether that be HDMI to HDMI or DVI to HDMI im not really fussed.

Ill also be plugging my xbox into the system and would love an easy solution to have the xbox audio out of the surround sound without switching the speaker cord between the soundcard and the monitor every time.

There is also scope for a nicer kb/mouse. Suggestions?

Thanks guys!

Ill say a few things.

1. Do you really need a quad core for a HTPC? you could save some dosh with a dual core
2. What SB 5.1 card? X-fi's have some issues with Vista , although most have been resolved with recent driver update i still hear alot of people complaining.
3. With some saved money on CPU or sound card... even just saving up a few more $$$ you could get the Logitech Z-5500's that will blow the X-540's out of the water.
4. and i agree with akhilles a passive 8600 would handle this well it also has the nessecary hardware that the current 8800GTS and GTX dont have. Possibly if you wanted better gaming the 8800GT would be better.