You can get an pci-express 2.0 card if you wish its backwards compatible.
So out of these four:
http://www.newegg.com/Product/Produ...description=&Ntk=&SpeTabStoreType=&srchInDesc
Which would fit best with this mobo?
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157148
Also:
Wouldn't the backwards compatibility cause the graphics card to slow down to equal a lesser card? If so by how much?