apnar - If you want to just have an AGP card, and then one PCI card and still be able to run 5 monitors, either analog or DVI, with possible different resolutions on each monitor, and different apps on each monitor, the best solution will come from a company called Appian. They are the leading video card source for CAD developers, so that's how I know about them.
One really nice card, found here:
Rushmore
would suit your needs very nicely.
It can be found here for $519.00:
http://www.isoutsource.com/velograph...D=259&CATID=46
Which would come to about $130 per head, not too bad
Oh, and the software bundle that Appian includes, HydraVision, is some of the best in the world for managing and automating the viewing experience.