I currently run
CPU: i5 2500k @ Quad 3.3
GPU: Geforce GTX 660 Ti
Ram: 8 gb DDR 3
Mass amounts of fan cooling and heat-sinks i don't care to list.
MOBO: ASUS p8z68v le
POWER: same as yours
HDD: standard sata 3/gb
Case: Maelstrom full tower.
I am able to run arma 2 at full settings online without a hitch. The only time my game will skip or stop working is when the server has lag in wasteland (Wasteland is a mod). This computer only cost me around 900 bucks when it was new.
The only thing i see wrong with your build:
your going to limit your case size to a mid tower ( give your parts room so they can breathe)
your going for a Micro Motherboard, that after looking up is junk. The motherboard is the backbone of any system, if you put junk in that's all it will give you in return no matter how big or small your parts are in power.
Invest more into your Motherboard.
Your GPU could be better. On the Pass-mark scale your card comes in at 3600 which isn't bad but for an extra 40 bucks you could get a geforce gtx 480 which has a rating of 4300. might not seem like much of a change but everything counts.
Every year PC Gamer comes out with a issue that tells you what new tech is coming out and how it helps or doesn't help. In that same issue they normally go over a cheap build and why they are using those parts.
I would look into that if was you.