Running Three Displays

Just built a new rig, everything is new except the gfx card. I've been holding off on buying one since I'm planning on upgrading my displays. I want to run 3 monitors and I am unsure of how much power I will need. I will most likely be buying three 22" monitors, either these Dell ones or their Ultrasharp equivalents. I play few games, typically Sc2 and occasionally Crysis; but I spend a fair amount of time using CAD programs as well as photoshop and illustrator. I was looking at either a gtx 680 or maybe even dual 670's but I'm pretty much clueless when it comes to this.

Thanks in advanced!