Now I've managed to obtain a picture of the card to be replaced, I need to find a suitable replacement for this:
It needs to support dual monitor, even if it uses one of those funny DVI/VGA splitters you get with the new Dell Optiplex, I have loads.

It needs to support dual monitor, even if it uses one of those funny DVI/VGA splitters you get with the new Dell Optiplex, I have loads.