if your going to go with that motherboard (its an expensive one, supports dual video cards!) you need a PCI-EXPRESS video card. NOT AGP. i decent budget card for pci-express is the x700pro or the x800gto. if you want performance, i agree with the other post, 7800gtx. x700pro sounds more your card though!
http://www.newegg.com/Product/Produc...82E16814102457
also, the x800gt is a very nice card for the price
http://www.newegg.com/Product/Produc...82E16814102636