Really extreme video setups are mostly overkill for now; unless you have a REALLY big monitor, want to run 16xAA (to my eyes you're into diminishing visual returns after 4xAA), or are making machinima, you'll see only slight improvements in your SL experience by going beyond a single 8800 or 9800; whatever bottlenecks you still have will usually be CPU or network limitations. (Just don't ever turn on Reflections/Everything; that one is a HUGE drain whenever media is playing!) But the upcoming shadow-enabled viewers will change that; rendering the shadows eats GPU resources, so GTX 200 series cards and SLI setups will really come into their own then. And if we ever see a version of the viewer that supports real 3D rendering such as the NVidia 3D Vision system, it's likely to need more GPU horsepower.
I haven't tried the specific card that the OP asked about, but it should be a solid performer for SL. Most NVidia cards, regardless of manufacturer, stay close to the NVidia reference designs, so there isn't a whole lot of difference in performance unless the manufacturer has overclocked the GPU and/or memory. The most common changes are to the cooling fans, so some brands DO have better or quieter cooling.