i7 4770 (No K) is fine. Overclocking will just degrade your parts lifetime, and really you don't need much more. Its a i7.
ASUS makes good mobo's AFAIK
RAM is good, I wouldn't go with any less actually. As for a manufacturer, I'd go with anything on the QVL [Qualified Vendor List] for the MOBO you pick.
SSD should be Samsung, they're the best on the market. [i just had my OCZ Drive fail twice in the last 7 months]
CPU Cooler should just be a Cooler master EVO or something, Liquid cooling [even closed loop] is pointless unless you're extremely into overclocking.
My 7950 does well in DCS. Sapphire DUAL-X is a good lineup for the 7950.
Also Windows 8 with the start menu mod is pretty nice, but the OS is whatever you please. If 8 only gives say a 3% increase in performance but makes you hate computers, it's not worth it.