Your video card in conjunction with the rest of your computer is processing the images and spitting them out at a specified resolution for your display. It is then your displays job (IE: Your monitor) to push that picture onto whatever size monitor/tv you have. As long as it's the same resolution, I HIGHLY doubt you would notice any difference in framerate.
On a quick follow up, some people may recommend certain cards depending on screen type. EX: If you have a huge High Def tv, you may want to get a card that has an HDMI output on it for better picture quality.