Critique my 800$ Micro-ATX Gaming Build?

Hello everyone  

I am going to have 750-800 dollars including the OS to spend on a desktop (M-ATX) capable of gaming! (I'll be playing new FPS titles such as: Call of Duty Black Ops II, Battlefield series, etc.)


A FEW QUESTIONS I HAVE:
1- Is everything compatible?
2- I'd like to stick with AMD FX because of the cheaper price; is there an intel i5 equivalent/better for the same price?
3- Windows 7 or Windows 8?
4- I know the GPU i've selected isnt the best for the money, but the motherboard only supports PCI-E x16 2.0, not PCI-E x16 3.0 like the ATI cards do. Id like to have a 7850HD, or a 7870HD because they are more powerful than the 560/570, but im not sure what motherboard is compatible with what cards. Can you help clarify?
5- If i were to overclock slightly, say .5Ghz per core in the future and end up with an AMD-FX, should i buy an upgraded CPU fan? Or will the stock pull it's weight?

Here is what I have picked out:
CASE: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

HDD: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

MOTHERBOARD: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

PROCESSOR: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

GRAPHICS CARD: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

DVD DRIVE: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

POWER SUPPLY: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

RAM/MEMORY: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

OS: http://www.newegg.com/Product/Product.aspx?Item=N82E168...


So, what do you recommend or suggest? I know i have a lot of questions, and i appreciate you fellow members helping me out and taking the time out of your day to help me out  . I reply quick so be sure to check back frequently