The computer is a cheapo Dell, with an i5 that is either Sandy or Ivy, can't remember off the top of my head. The cheapo Dells cut major corners on their motherboards, so I wouldn't expect Crossfire to be a viable solution. I could find out if necessary, though.
Monitors have yet to be purchased. I was thinking four of these: http://www.amazon.com/gp/product/B005LN ... PDKIKX0DER
They are Dell, 1080p, 23" have DisplayPort, and can swivel to portrait. They are IPS. I suspect I don't need the last word in color reproduction for trading monitors, but enhanced viewing angles might be nice, and I can't really find cheaper monitors that can swivel to portrait. I'm thinking 4x1 portrait.
Currently, I have some computers that have one monitor connected with DVI and another with VGA, or one with HDMI and one with VGA. Sometimes identical monitors look different then. The color is a bit off on one, or one is fuzzier. I suspect using only DisplayPort from GPU to each monitor would fix this. But maybe the problem is that VGA is analog, so as long as I stick to digital cables I'll be fine?