To tell the truth these Macs will last you a hell lot of time. Because of the processor About graphics well the 1900 is pretty good and you could sell the whole computer easily for a good price on ebay or elsewhere when the graphic card gets old. To tel the truth if you are such a gamer then I wold recommend that you go for a big HDTV coupled with a super home theater and play an XBOX 360 or PS3 on it. These will last way longer without worrying about performance and all. I would do that if I were you because of the amount of money you are ready to spend. The consoles will be ore powerful, in High Definition and there are many other advantages. You could start another discussion to determine whether consoles are good for you.
BYE BYE