That PSU will work just fine with a single card setup. However, if you choose to upgrade and want to run 2 cards you will need to upgrade again. Refer to this article for complete info: http://www.tomshardware.com/reviews/geforce-radeon-power,2122.html
. I just purchased a GTX 260 C 216 and according to that page I can SLI them because I have 3 X 19A 12V rails on my 650W PSU. It would cut it close, but it would be possible. What are your system specs?