I love re-purposing second hand computers that people always give me as payment for pc/network help and thought it would be great to have one as my security camera dvr. My current cameras are a mix of brands and models and I have them setup on a av switch on one tv, so I have to manually click the switches to change cameras. Some of the cameras also have audio. I would like to find a dvr card that would support audio and not require a specific brand of camera just accept any camera av input. Also would like to have the grid view of cameras to see all at once. Any suggestions or advice?