Well if your mobo can handle it, then I'd say get two really cheap PCIe cards. Do you already have the MoBo? What is it?
Do you have 2 PEG (Pci Express Graphics) 16X slots or just one, if you only have one PEG slot and then a buch of PCIe 1-4X slots, then get a cheap 16X card and then an similar 1X card (keep them similar for drivers, although in your environment you might almost be ok with the standard M$ display drivers).
It will give you more options than the Matrox (be sure to not the resolution limits), however since I love Matrox (especially their multi-monitor solutions) so if it fits your needs, enjoy!!
http://www.matrox.com/graphics/en/press/guides/th2go/