Going dual screen, GPU recommendations?

[moneybagman]

Hey, I am building a new computer and I am pretty new to this. I was planning on going dual screen and I wanted a nice graphics card for gaming and visual design (I use Photoshop and CAD). I am thinking about getting two ASUS VW246H 24" (Newegg.com - 24-236) and I was considering the Radeon Sapphire HD 7870 (Newegg.com - SAPPHIRE Radeon HD 7870 GHz Edition OC 2GB 256-bit GDDR5 PCI Express 3.0 x16 HDCP Ready CrossFireX Support Video Card (11199-03-20G).
Will I require two of these graphics cards? I was only planning on getting one.
Any ideas, comments, suggestions?

 

[stormy13]

One is more than enough. Just don't plan on running many (more like any) games on both at the same time as very few (can only think of a handful that do) support running on two monitors. Not only that but if you're playing a FPS type game, the crosshair/aim point would be split right down the middle, makes it rather difficult to shot anything.