3 monitor surround setup

[Allizia]

Anyone know what else I will need to get this to work:

http://www.youtube.com/watch?v=Wf7St4WQclk&feature=fvst

I know I will need a third monitor obviously, just not sure if I will need a 2nd graphics card etc.

Current setup is:

Antec Nine Hundred ATX case w/ top 8" and front and rear 120mm fans
Top mounted USB, firewire, audio and mic outputs
Corsair 850 watt silent power supply w/ single power rail and quad SLI/Xfire support
Intel Core i7 930 quad core CPU OC to 3.8+ GHz
Thermalright Ultra Extreme 120 heatsink w/ bolt-thru 1366 mounting kit
Scythe 28 db 120mm fluid dynamic bearing fan
ASUS Socket 1366 ATX overclocker's motherboard
Gigabit LAN and 8 USB onboard
High Definition 7.1 audio onboard
6 GB (3 x 2048MB) DDR3 1600 SDRAM (16 GB MAX MEMORY)
128 GB SATA Solid State Drive for OS and games
2 x 1.5 TB SATA-2 hard disk drive for storage (RAID 1 redundant mirror array)
24x Dual Layer DVD/CD recorder (black)
GeForce GTX 480 (Fermi) 1536MB 384-bit GDDR5 PCI Express 2.0 x16 HDCP Ready Video Card
Microsoft Windows 7 Home Premium 64 bit OEM
ASUS 26" flat panel LCD monitors (1920x1200 full widescreen)