It has been 4 years since I built my last PC and the only internal component I have upgraded was the video card (GTX 690 to GTX 980Ti). Below is a notional build. I am looking for any and all input on what it is good or bad.

Time frame - By the end of Jul (spare Windows 8 code I can use to get Windows 10 free)

Budget - Whatever it takes within some reason.

Usage - Primarily gaming. Occasional CAD, photo and video editing.

Existing Components - Monitor (Dell P2715Q - 4k), Keyboard (Logitech G11), Mouse (Logitech G502), Speakers (Klipsch Pro Media Ultra 5.1), Power Supply (EVGA 1200 P2 - got it half price when I bought the 980 Ti)

Possible Components:
Case: Cooler Master HAF X (I used for my last build and like the front hot swap bays)
Video Cards: Two EVGA 1080 GTX FTW
Motherboard: EVGA X99 FTW K
CPU: Intel Core i7-6950X
CPU Cooler: Thermalright Silver Arrow IB-E Extreme or Le Grand Macho RT
Memory: Gskill TridentZ Series 4 x16GB
Boot Drive: Intel 750 Series 1.2TB
Data Drive: WD 4 TB Black
Optical Drive: LG WH14NS40
Firewire: Vantec 3 port (need it for scanner and video camera)

I am not wed to any particular store or component at this point. I have no desire for water cooling.

Tell me where I can improve or went overboard. I am already thinking i7-6850K may be better choice