Triple monitor/vid card help

[Darth Yoda]

Hi guys!
My set up is a Gigabyte EP-45UD3P mobo, 4870x2 vid card, Intel 3.3 dualcore, and 4 gigs GSkill memory on XP Pro. I'll be playing CoD4 or BFBC2 with some Crysis and Far Cry 2. I would like to set up three monitors. It looks like I'll have my Dell 2007 as a center monitor with 2 19 inch unknowns as sides. As I understand it I would need another Vid card or TH2G.
What are your suggestions as to completing the three piece setup?