I very much doubt that car will work with your PSU.
What resolution are you using to game at ?
Your system would be best suited to a lower powered card. Do you know if the PSU has a PCIE cable to power a GPU ?
I would probably play safe and stick with a card that does not need extra power.
Something like this http://www.techpowerup.com/reviews/Powercolor/HD_6670/1.html
If you look at the review you will see that the 5750 is the next card up and its possible to get a version of that card with no extra power needs.
If you have a PCIE cable on your PSU then you could run a slightly better card with modest power needs.
Your CPU isnt that strong and you would start running into restrictions with a card that was too powerful.
This means the card could run faster even if only slightly but cant as it is held back by the CPU.
This is what is (technically incorrectly) refereed to as a bottleneck.
Any questions please ask.