Just had a quick google and it looks, from the Asus website that your A8V board only supports an AGP graphics card. That card you've talked about is running on PCI-Express which would require you to upgrade your motherboard.

If you like nVidia then you might want to look at something like a GeForce 7300 GT 512MB such as this one from overclockers:

http://www.overclockers.co.uk/showproduct.php?prodid=GX-094-OK&groupid=701&catid=56&subcat=411&name=OcUK%20GeF orce%207300%20GT%20512MB%20DDR2%20HDTV/DVI%20(AGP)%20-%20Retail

Hope this helps you out a little bit