That is very similar to my rig (see sig) and i play WoW alot, and with my UI mods eating VRAM, i still get 60FPS on high atleast.
The Mobo isn't all that expensive as far as mobos go and it should suit your choice of processor. However you probably won't be able to use that RAM. It's a triple channel kit and the mobo only supports dual channel setups. I recommend this instead
Newegg.com - CORSAIR Vengeance 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 Desktop Memory Model CMZ4GX3M2A1600C8
the blue cable is called a VGA. I assume you mean a DVI to VGA adapter there, and basically it just crosses the correct pins of the VGA to the applicable ones on the DVI, so the signal is kept crisp eventhough it's been adapted to run on a different medium.