Pimp my Dell 710XPS into a HTPC

Hi,

I just purchased a new system for my home office. It has XP Media Center installed so I want to try to use it. Here is my system:

Office

Dell 710 XPS
Intel Quad Core 2.4 Q6600
4G Ram
8600GTS (SSL)
320G Harddrive
XP Media Center
Cox Cable
Cox Cable High Speed
Router
Netgear Power Plug to Router

Home Theater

XBOX 360 (VGA to Projector RGBHV)
XBOX 360 HDDVD
Sony PS3
Netgear Power Plug
Denon 5700 (Componet to Projector)
JVC G1000 Projector (1365x1024 Native)
Opo Digital 970 Upscaler DVD Player (By far the best picture quality of any source in my system, Componet 1080i)
Cox Cable HD DVR

Objectives

1. Stream dvds to xbox 360 with quality equal or better than the opo970.
2. It would be great to surf the internet in the home theater room. Real surfing not a 10ft interface.
3. Stream music
4. Stream photos
5. Get rid of $13 a month Cox Cable DVR

Please include detailed hardware and software recommendations.
Thanks in advance!

I spent $1799 to save $13/mo and I bet it won't work. Ya Ya. No really as I said I needed a new office machine. It will live in the office and hopefully stream videos via the Xbox 360 in the home theater room.