The above builds look good and would serve you well, there are a few changes I would make personally though.
CPU - Agreed, I'd go for the i5-6600k. No groundbreaking performance increases but means you get the new 1151 socket and DDR4 RAM etc.
CPU Cooler - The H55 would probably do a slightly better job than the 212 Evo but it costs a lot more, it is a case of personal preference really. My preference is to stick with air cooling because it is cheaper, has almost no risk and is often quieter because there's no pump noise.
SSD - M.2 would be faster but you won't notice a difference in games, even on the desktop the difference is small. I'd probably get a SATA drive.
PSU - The CX series are OK for the price but I'd get something a lot better at this budget, it's Seasonic or nothing for me personally. All of their PSU's are great, never seen a bad review on any of them. I wouldn't bother getting enough power for an SLI setup unless you plan to add the other card in the next month or two, by the time new cards come out they will be a better value upgrade than SLI.
OS - Completely personal preference, I'm on W10 myself and I like it but go for whichever OS you want.
Monitor - I'd go for 1440P IPS at this budget, Freesync and G Sync aren't really affordable for you because you'd also need a $700+ graphics card to take advantage of it.
Keyboard/Mouse - Totally personal preference again, some people don't even notice the difference between mechanical and standard keyboards so I'd see if you can test one out at a shop before splashing out on one. I'd try out some mice before buying one as well, you can't just go from a spec sheet when buying a mouse and keyboard, it is completely personal preference.
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i5-6600K 3.5GHz Quad-Core Processor ($251.98 @ Newegg)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.99 @ Newegg)
Motherboard: Gigabyte GA-Z170-HD3 ATX LGA1151 Motherboard ($114.99 @ Newegg)
Memory: Crucial 8GB (2 x 4GB) DDR4-2133 Memory ($53.90 @ Adorama)
Storage: Crucial BX100 250GB 2.5" Solid State Drive ($83.99 @ SuperBiiz)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($47.78 @ OutletPC)
Video Card: PowerColor Radeon R9 290 4GB TurboDuo Video Card ($252.98 @ Newegg)
Case: NZXT S340 (Black) ATX Mid Tower Case ($54.99 @ Micro Center)
Power Supply: SeaSonic S12II 620W 80+ Bronze Certified ATX Power Supply ($68.99 @ SuperBiiz)
Operating System: Microsoft Windows 8.1 OEM (64-bit) ($88.88 @ NCIX US)
Monitor: Acer K272HULbmiidp 60Hz 27.0" Monitor ($329.99 @ Micro Center)
Total: $1368.46
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-08-27 08:51 EDT-0400
That would give slightly better performance than the build you quoted and for a bit less cash, leaves enough room for a 1440P IPS monitor and $100-150 for your mouse, keyboard and headset. gets you a more stable PSU and you'd be on the new 1151 socket as well. The R9 290 isn't as overclockable as the GTX 970 but still similar performance for a lot less cash.
This shows that even at 1440P it averages 50FPS on Crysis 3 on high with FSAA:
http://www.anandtech.com/show/7481/the-amd-radeon-r9-290-review/8
EDIT: Sorry I just realised there are only certain stores you can buy from, you could aim for similar parts from those stores though.
Facebook
Twitter
Instagram