yap.. That is a pretty accurate totem pole. Also since those rankings were made a geforce 9 midrange card "9600GT" was released... it sits between an AMD HD3870 and Geforce 8800GT in performance, but has a few new features as far as video playback, open GL 2.1 support, etc... And is very cheap. Probably the best bang for the buck card in the world right now.
The rest of the GF9 series is coming out march. And AMD is slashing prices in response.
The nice thing about that ranking page is that it ranks video cards by power, not by performance/price. So you can look at a few cards at current market price and get a good comparison for them.
EDIT: Dear god, pci video card? why? you mean you have a motherboard without a PCIe OR a VGA slot?
Listen, if that is the case, plunk down 60$ for a new motherboard and get a real video card. They actually DO make motherboards that work with old CPUs and RAM and allow you to plug in a pcie card, ASROCK makes them.
I don't think this card meets the minimum requirement, and you really should have no reason to play sins at anything below maximum settings. It is quite an awesome looking game and light to boot.