Your first problem will be finding a decent PCI graphics card. That slot is not the PCIe standard that we have today. Here are some PCI graphic cards: http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007709%20600007853&IsNodeId=1&name=PCI#
Most of them come with a low profile bracket included. Not that the bracket will do you any good, but it means they are adaptable to a low profile case. You may be able to use one without the bracket in place... just let the card stick thru the opening. But it would only be secured by the slot itself.
Is that the original board in that case? Or did the case originally have a different board in it?