That card doesn't seem to have much power behind it, I'd try to find some reviews of people that have bought and built an eyefinity setup with the specs you're shooting for with it prior to purchase.
The card you posted, and the review are of 2 separate things (pardon me if you already knew that). The Eyefinity 6 class are 2GB cards with expanded capabilities and have been generally very well reviewed. Look for 5870 E6 cards to match up with the review.
