Yes, your motherboard actually does contain an AGP 8x VGA interface. (ASUS reference is at
http://www.asus.com/products.aspx?l1=3&l2=12&l3=31&model=179&modelmenu=1 AND
http://www.asus.com/products.aspx?l1=3&l2=12&l3=31&model=179&modelmenu=2.) This means that the video card you replace the All in Wonder with must meet that specification unless you are prepared to switch out the board.
However, as the card you have indicated above is a PCIE x16 card, that may represent additional compatibility options. (The reference for this card is here:
http://ati.amd.com/products/radeonx1300/aiw2006pcie/specs.html). This is a bit confusing, given that the motherboard specs indicate an AGP 8x interface. There is the indication on the "modelmenu=2" page that the MB includes 5 PCI expansion slots, but there is no mention of any PCIE x16 interface.
It is often best to return to the site of the manufacturer, or a respected seller, to check for compatibility with the specific brand and model of your PC. This would likely be the best approach, and if you would like for me to help with that, please post back with the information.
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