I used triple/3screen for a while a couple years ago or so, it's great. Try and get 144hz 1080p monitors if you can afford them, or at least decent 60hz ones, be sure to really google the snot of whatever you look at in terms of gaming performance.
As others said, nVidia provides what you need to do this these days, be aware of what connection ports your GPU card has, and what type the monitors use, as you'll need to figure out which cables you need, and how to set them up, ie displayport, HDMI, DVI. Also, make sure you have enough desk/surface space for them, measure first and be certain, both in width, and also depth behind your desk/table/whatever. There are lots of 3 monitor (or more) stands in different configs out there, I think I paid around one hundred fifty for a decent one that held all 3 of mine on a single center stand.
http://www.ebay.com/bhp/3-monitor-standThe only disadvantage are the bezels, but you'll quickly get accustomed to them, and won't even notice them after a short time. The slimmer the better though IMO, again, google the model you decide on and get other gamers opinions on it.