the extra graphics ram will only be used a very tiny bit in some of the highet games and is definatley not worth the money with that cpu you probobally couldnt run any of those games anyways and with a 9600 the gpu probobally won't be powerfull enough too
It depends on how many piplenes the 256 has. And you prob won't notice any difference in gameplay. Most all games don't even need 128mb to run at max settings. 256 is a little overkill at this point in time. Go with a 9800 Pro 128mb.