Noob that needs suggestions/tips with gaming build

Hardware Build a PC
1

First off I am going to list what I am planning on playing and then my planned build.

Games:

Arma 2 and when it comes out Arma 3

Total war games

Battlefield 3

and etc... I would like to be able to play on atleast High settings on all games on a higher res

Planned Build ($850 Budget):

(I am looking at Intel parts and am 100% open to suggestion and also if you could recommend a cheaper build that can do what I ask please do link me to it or list the parts. Saving money would be a huge plus)

-Cooler Master Elite 430 - Mid Tower Computer Case with All-Black Interior (RC-430-KWN1)

-AMD Phenom II X4 965 AM3 3.4Ghz 512KB 45NM 125W 4000MHZ

-GIGABYTE GA-990FXA-UD3 AM3+ AMD 990FX SATA 6Gb/s USB 3.0 ATX AMD Motherboard

-HIS 7870 IceQ 2 GB(256bit) GDDR5 2x Mini-DiplayPort HDMI DL DVI-I (HDCP) PCI Express X 16 3.0 Graphics Card H787Q2G2M

-2 of Corsair XMS3 4 GB 1333MHz PC3-10666 240-pin DDR3 Memory Kit for   Core i3 i5 i7 and   CMX4GX3M1A1333C9

-Cooler Master GX - 750W 80 PLUS Bronze Power Supply (RS750-ACAAD3-US)       

-Kingston HyperX 3K 120 GB SATA III 2.5-Inch 6.0 Gb/s Solid State Drive SH103S3/120G       

 

ALSO if I need any extra cooling or even tools for putting it together please let me know.

Pretty much what I need is for somebody to hold my hand through the whole build because as much as I love gaming and computers I am pretty much  a 0 out of 10 on computer smarts.

Thank you in advance for any help I recieve.

2

Lower your power supply to 600w and get 8gb of 1600mhz ram. No guarantees you will be able to run Arma 3 (on high) with that CPU.

3

I am also buying 500gb hard drive which I did not list..

And in the case of the CPU holding me back, what would you suggest?

4

Im not very familiar with US prices but I found this on a previous post on a build with a budget around yours. Credit to Z: http://pcpartpicker.com/p/zskO This build will be able to run all those games listed above on high/max @ a constant 60fps+.

5

I personally have that motherboard and really like it for the price, no complaints at all. For the processor, might I suggest spending like 30 more bucks and getting the FX-6300? I've read some good reviews (http://bit.ly/TBnY4M) and can be OC'd nicely. 

6

I am very much considering the build that Hopperbus linked so thank you for that and whomever originally posted it. On another note, do I need any extra cooling or thermal paste which I dont really know what that is but it says its normally purchased with that processor?