I'm totally hijacking, here. But how do you interface the devices? This is blowing my mind!
I added a video card that has an s-video output, which hooks up to a little s-video to coax converter box (dirt cheap on ebay), which then hooks to the TV. So the TV is essentially a second monitor. I then use EventGhost and scripts set up to switch to the B&W for video and audio (switching between hdmi audio and the normal audio output). I don't know if you're just curious or seriously interested but feel free to PM me for more details if you want me to go into more depth!