Easiest solution?
Get one Matrox G450 MMS Quad. They come in a pci version. List price is around $600 +/-, but buy it new via Ebay for less. You can then add another monitor at a later date. Even if you don't need another, a quad array on one of the various monitor stands available looks really cool.
Or get 2 of the dual g450's, pci. Also, via Ebay, but harder to find than the AGP's, which are CHEAP. I picked one up for $50. I don't use the thing though cause I run a quad via my AGP.
Read up at matrox.com
Jay