If you were to buy the i7-6700 then, for gaming, i would've suggested for i5-6600 instead. But since you get it for free, it will do.
About PSUs, i prefer Seasonic. For your GTX 1080, a 500W range, in this case a Seasonic G-550 ($69.89).
pcpp:
http://pcpartpicker.com/product/DPCwrH/seasonic-power-supply-ssr550rm
It's 80+ Gold, semi-modular and a solid Tier two PSU.
Also, refined your build a bit.
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i7-6700 3.4GHz Quad-Core Processor (Purchased For $0.00)
Motherboard: MSI H170A Gaming Pro ATX LGA1151 Motherboard ($122.99 @ SuperBiiz)
Memory: Kingston HyperX Fury Black 8GB (2 x 4GB) DDR4-2133 Memory ($48.99 @ Newegg)
Storage: SK hynix SL308 250GB 2.5" Solid State Drive ($65.99 @ SuperBiiz)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($48.89 @ OutletPC)
Video Card: MSI GeForce GTX 1080 8GB GAMING X 8G Video Card ($653.99 @ B&H)
Power Supply: SeaSonic G 550W 80+ Gold Certified Semi-Modular ATX Power Supply ($69.89 @ OutletPC)
Total: $1010.74
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-11-10 12:14 EST-0500
Few words.
Changed the MoBo to a Gaming Pro version since it has RGB LEDs for eyecandy.
Picked 2x 4GB of RAM, leaving 2 RAM slots free for future upgrades.
Put in the best SSD for OS (
proof here) and 1TB HDD for storage.
Went with a Gaming X version of the GPU to match the MoBo's black&red theme.
And lastly, put in great PSU that comes directly from the best PSU OEM, Seasonic.
Didn't put the case in since case is a personal choice. Though, can give suggestions if you like.
Oh, if you don't have the stock Intel's cooler that comes with non-K CPU, you also need to buy one.
Here i suggest Arctic Freezer i32.
pcpp:
http://pcpartpicker.com/product/rz7CmG/arctic-cooling-cpu-cooler-acfre00004a
I got the same CPU cooler in my current Skylake build with i5-6600K, though i upgraded mine to push-pull system with another 120mm PWM fan (Arctic F12 PWM PST).