I would say almost ALL modern video card support dual displays. You will just want to make sure it has the outputs you need. As far as displaying TV on your screen, you will need a TV tuner card to hook up to cable. Unless you are using a cable or sat box and just need video input. In which case I would almost just say get a monitor that you can connect the box directly to, or a monitor that has a built in tv tuner. Unless you are going to record and stuff a good tv tuner card can get pricy.