Only one DVI connection. But you may have to buy a DVI cord if you dont have one.
**Also, if you need to hook up a VGA cord to your GFX card, just use the DVI-VGA adapter.
the 6800XT should be good for your cause. I have the same card. Gets good framerates in CS:S and can display the resolutions you need.
If you have a DVI cord, you might as well hook it up to the TV and see how it looks. When playing games, you may have to adjust the screen for the TV.