想upgrade部機玩gta4

依家係
cpu:amd Athlon X2 3800+
BOARD:asus M2V
Display:asus nvidia 7300GS
HDD:不明160GB
火牛:不明400W
RAM:1Xkingston DDR2 800 2GB,1Xkingston DDR2 667 2GB
想用4000蚊倒
display換4870(1gb)得唔得
其他$應該點分佈