I personally have a MSI Hawk Talon Attack 460 for swtor and it runs everything on the highest settings (+tweaked some settings even higher. The card runs a bit slow in busy sections like the imperial/republic fleet but runs fairly smooth everywhere else. No bugs or problems playing the game with this card at all.
All of these cards are fine. I personally recommend a 460 though. You can get it in that price range. Keep in mind you get better drivers (most of the time) and Physx capabilities with an Nvidia card (Although Physx isn't exactly used much in games, you will see immense framerate improvements in games that are using it. For example, Batman) and better overclockability.http://www.newegg.com/Product/Product.aspx?Item=N82E16814130750
Vettedude is right though, you might want to look into a bit heftier power supply otherwise you could run into power issues (crashes) or worse and short that power supply and possibly wreck everything in your computer. If you put a lot of strain on your power supply, it dramatically reduces the life of the unit. Bigger (wattage/rms) generally better with power supplies and it gives life to everything in your computer. Best not to cheap out on it either.
Processor: - Core i7 920 @ 3.6 ghz