The GTS 250 is a 9800GTX+ that uses less power and nothing more, and my 9800GTX+ is just fine, no it's not going to max out BF3 or Skyrim, but for $40 new you are not getting anything better. (unless you get a good deal on a secondhand card, but then longevity/reliability becomes an issue)
Also, stop buying fans, cheap fans suck donkey dick and you don't need them as much as you might think you do.
Get a PSU, the Antec NEO ECO 520 is your best bet IMO
How about a fan to blow air INTO the computer? The GTX 250 is a 140W card, so it may heat up a bit. Also the fan was rated 5 eggs on newegg, so it should at least be semi-decent. But if you really say so, maybe I don't need one. Now about the PSU. You sure you got the right wattage? Because the wattage scares me. Also that thing costs $60 dollars. Can you go cheaper? And do I still need to upgrade my CPU? Be back in like 30 minutes.
Edited:
Found a PSU with a decent rating, even compared to the Antec you suggsted. 485W. Want to know if it will work with all my parts. http://www.newegg.com/Product/Produc...scrollFullInfo
And I just realized my brother has a SATA hard drive he doesn't need.