Thanks for all the advice and input!
I didn't order the parts yet, but I did put them together - seems fine to me indeed, the price is also absolutely ok.
Yet there's one thing left I'd like to ask:
I played a bit around with different parts and piled some really nasty things - which brought me to another build.
I know that it probably will be utter overkill for WoW etc., but it seems quite tempting to me
The question isn't necessarily "Do I need it?", but more like: "Would I notice ANY difference compared to the setup(s) mentioned above in a real world environment?"
MoBo: ASUS Rampage IV Formula
CPU: Intel Core i7-3930K
RAM: G.Skill RipjawsX 1866, 4x4GB
GPU: MSI NVIDIA GTX 680 Lightning
SSD: Corsair Force GT 120 GB
HDD: WD Caviar Black 1TB
PSU: Corsair AX850
Heatsink: Corsair H100i
Case: Coolermaster HAF-X RC-942
Fans: Corsair SP120 x4