My first impression is that you like the color blue.
I guess you are comitted to AMD since you already have the cpu , with gaming however the Intel Sandy Bridge rules. The AMD cpu's offer a cheap alternative to Intel but they are lacking in gaming power. The video card is a good choice for your budget. You could have built a better gaming computer if you had posted before you bought anything.
The case you listed is ok but a computer case is one of those things that is more of a personal taste. The three things that you could change is the ram motherboard and the psu. You really don't need 16gb as you will never use half of it. A lot of people think that the more ram the better but for games you really don't need much. I had task manager open while playing MW3 and I was using 3gb of ram for the game and over all 5gb. SO to save some money here and maybe put it towards a better psu would be a good idea. OCZ is better known for memory and not psu's. The XFX brand is however a good choice but with crossfire in the future you either have to address the psu now or when you get the second card. You can look at this psu;
I'm afraid the price has gone up a little but you do have to make some choices as to what you want to do. Crossfire means a different MB and a larger psu. If you want to stick with what you have listed then later when you want to crossfire you will be changing out the psu and MB and you will either have to try and sell those parts or keep them on a shelf.