My son runs 2 monitors quite successfully off one graphics card and was advised to use a Matrox Parhelia card when he was in to film editing a while back - which is really graphic hungry ....
http://www.matrox.com/graphics/en/press/guides/display/I don't know what he finally got but I don't think the card is the issue so much as the outputs - I don't think you need 2 cards to run 2 monitors.
Simming is not about monitors per se - you can use graphics drivers to spread one game across 2 screens without needing more powerful graphics - as long as the card has 2 or more monitor outputs you can do all manner of things with the screen displays - but beware of VGA v DVI
see this.......
http://flyawaysimulation.com/article3803.html and this
http://flyawaysimulation.com/article3804.htmlOf course the ultimate is 3 monitors - one straight ahead and a left/right view as well ......

There is loads of help out there - as always Google is your friend - with the right questions
