Basically, because I have 2 7900 GS OC graphics cards in my computer, the case is a little cramped. I want to use my computer as a DVR, TV, etc.

I was reading/watching that streaming the video over the internet, it downgrads HD to 640x480, but it still looks better than regular broadcast. This doesn't bother me really, but if it's on my home network, will it stream in HD? (I assume 720 or so)

 My next question is, will it work with an OTA HD antenna? If so, which ones do you guys recommend? 

If you have any other recommendations on how I can get a good HD signal into my computer with DVR fucntionality using and OTA antenna, I am all ears. But as far as my research goes, this seems to be the only way to get HD into my computer without trying to squeeze a PCI card in there.