welcome to the forum,
your rig is so fine but i need to get you noted about few things:-
1- If you're going to be gaming above 1080P so CF will be a good option for increasing performance and good way for better FPS
2- i wouldn't crossfire HD 6870s because of Microstuttering explained recently by Tomshardware http://www.tomshardware.com/reviews/radeon-geforce-stut...
3- Cooler Master GX series has awful reviews and too many not recommending them in CF or SLI setups
4- if money is not a problem get a better PSU and better GPUs such as HD 6950s or wait until the 7K series comes it's 28 nm with 1 GHz GPU frequency, new XDR2 technology which is said to be twice faster than GDDR5
Sorry I should've been a little more specific. I plan on gaming at 1920x 1080 p on one monitor. Well that is a bummer to hear that. Money isn't really an issue, but I just built this rig about 1 month ago. However, I may just buy a 6950 in a couple of months, depending on how I feel my 6870 is performing with newer games.
a single HD 6870 is not good enough for that resolution, and the link i provided shows how even a Crossfire of them is doing in both DX11 and DX9 and they do a creepy performance.
tell me what's your plans ?
Well, as far as what I plan on doing concerning my HD 6870, I'll probably test it out for a couple more months. I just got it last month, so I figure might as well get some juice out of it until Skyrim, BF3, and other more demanding games are released. If it's not performing to the standards I want, I might just buy a single 6970 and see how that goes.
Honestly I kinda regret not buying a higher end card, but I did not want to throw down that much cash since it was my first build and I was not sure how'd it turn out.
i would suggest to stay with a single HD 6870 until the 7K series come out, a high end GPU such as HD 7950 is said to be performing close to HD 6990, so you can wait and grab one of those 7K and thus you won't have to upgrade your PSU or spend money on new GPUs that might become frustrating when the 7k series is up