You can use Boxee, which can be used underlinux for Low resouce use, and the only time you need a high end graphics card is if you are running a bluray player, and you have the need for the HDCP handshake for the content, including the HDMI connector, but adapters can be found for taking DVI-D to HDMI. Most of the time if you need not transcode, and are just streaming wysiwyg, you should be just fine.