the gtx 460 768mb is a great card similar in performance to the HD5830 and currently provides alot of performance for the price. i would recommend going for a HD6850.
the power supply is pretty good for the price, but you should spend a bit more and go for a power supply that has over 80% efficiency. if your not overclocking then that cpu is fine, but if you are, just go for the cheaper x4 955 and you can reach the same clocks easy.http://www.newegg.com/Product/Product.aspx?Item=N82E16819103808
im guessing you have your own hard drive, operating system and optical drive.