Advice on cooling & mobo

Budget:
Max $3,000 (tower only)

Expectations:
Play games at 60+ fps on high settings on 1440p monitor (likely 16:9 but also considering 21:9). FWIW, I'm looking at monitors with G Sync and at least 100hz.

Usage:
100% gaming

Special Needs:
The computer will be installed in my home theater and connected to surround sound.

My Questions:
1) Will the stage 1 air cooling be sufficient with the overlocking?
2) Should I be looking at an upgraded mobo for my use, or is the default one ok?
3) I'm also considering a 960 EVO instead of the 850, but from what I've read they don't always work as the primary storage/boot drive. Would it work ok in my setup?
4) Will the integrated audio on the mobo get me 5.1 or do I need a separate sound card to accomplish that?
5) If you have any other feedback, please let me know.

Saved Ticket #: 1583821

Specifications:
Chassis Model: Special Deal Hot Seller - Digital Storm Apollo (Black) <br><strong></strong>
Exterior Finish: - Standard Factory Finish
Trim Accents: - Standard Factory Finish
Processor: Intel Core i7 6700K 4.0GHz (Codename Skylake) (Unlocked CPU) (Quad Core)
Motherboard: ASUS Z170-E (Intel Z170 Chipset) (Up to 4x PCI-E Devices)
System Memory: 16GB DDR4 2666MHz Digital Storm Performance Series <br><strong></strong>
Power Supply: 750W EVGA SuperNOVA <br><strong></strong>
Expansion Bay: - No Thanks
Optical Drive: DVD-R/RW/CD-R/RW (DVD Writer 24x / CD-Writer 48x) (Internal)
Storage Set 1: 1x SSD (1TB Samsung 850 EVO) <br><strong></strong>
Storage Set 2: - No Thanks <br><strong></strong>
Storage Set 3: - No Thanks
RAID Config: - No Thanks
RAID Card: - No Thanks
Internet Access: High Speed Network Port (Supports High-Speed Cable / DSL / Network Connections)
Graphics Card(s): 1x GeForce GTX 1080 8GB (EVGA ACX 3.0) (VR Ready) <br><strong></strong>
Sound Card: Integrated Motherboard Audio
HPC Processor: - No Thanks
Extreme Cooling: AIR: Stage 1: High-Performance Copper Heat Pipe Cooler <br><strong></strong>
HydroLux Tubing Style: - Not Applicable, I do not have a custom HydroLux liquid cooling system selected
HydroLux Fluid Color: - Not Applicable, I do not have a custom HydroLux liquid cooling system selected
Cable Management: Premium Cable Management (Strategically Routed & Organized for Airflow)
Chassis Fans: Corsair Airflow Performance Edition Fans <br><strong></strong>
Internal Lighting: - No Thanks
Airflow Control: - No Thanks
Chassis Mods: - No Thanks
Noise Reduction: - No Thanks
LaserMark: - No Thanks
Boost Processor: Stage 1: Overclock CPU - Up to 4.4GHz (Depends on Cooling and Motherboard) <br><strong></strong>
Boost Graphics Card(s): - No Thanks, Please do not overclock my video card(s)
Boost OS: - No Thanks, Please do not tweak the services on the operating system
Windows OS: Microsoft Windows 10 Home (64-Bit Edition)

Thanks! I appreciate the input!