Building computer need help for gaming

hi guys so i finally got a job and i want to upgrade my pc finally to play crysis and all the new games that have all the eye candy out. i still want to use my case, hard drive, and power supply so those should cut down the cost. these are the parts i want to buy. let me know if they are ok are not.

http://www.newegg.com/Product/Prod [...] 6813131339 its an asus m3A79-T deluxe for my motherboard

http://www.newegg.com/Product/Prod [...] 6819103291 amd 9950 BE for cpu

http://www.newegg.com/Product/Prod [...] 6814102795 ati hd4870 1gb version for gpu

http://www.newegg.com/Product/Prod [...] 6820227289 and 4gb of ocz hpc ddr1066 for the ram. any input would be great...thanks guys.

its an antec neo power 550w and no crossfire i dont need to spend more money on a 10% gain