New system requirements question

I am preparing to upgrade from my 4-year old system.

I am really interested in trying to use the new AMD Dual-CPU in the new system. Here are the very basic items I am looking at:

CPU - AMD Athlon 64 X2 4400 / AMD Socket 939
RAM - 1 DDR400 GB matched pair
HDD - 2 SATA and 1 ATA/133 no RAID configuration
MB - Asus A8N-SLI Premium
Video/Graphics - Need to be able to connect to Cable TV service and edit video for DVDs and websites. Is there one Graphics card which can handle this? If not, can the Asus mobo handle two video cards, a PCI ATI AIW and a PCIe card?

Not interested in all of the bells and whistles.

Any help will be greatly appreciated.