Please tell me what you think about my first pc gaming build

Budget: None as long as i can justify spending the money

Operating System or Peripherals (Monitor, Keyboard, Mouse, etc) needed? Yes monitor is 1ms response time (for mmo or fps games) 144hz 2560x1440. The reason i didn't go with 4k is the response times and refresh rates aren't up to snuff in them yet, i might get a 4k tv for rpg and games like it.

Where you are located (to determine if you are near a Microcenter) Eastern Connecticut

Any other personal preferences or requirements (such as overclocking)? The board is oc compatible if I wanted to do it in the future and has space for a second video card, that is also why i went with a higher watt power supply.

Any suggestions will be appreciated like if i need more or less of something or if some of these parts will outperform other parts in the build. Is that cooling enough or to much for the cpu or if i wanted to overclock it. And for the os i should be able to get a old version of windows 7 and upgrade to windows 10

Also some questions I have: Is it adequate for gaming in 2k? Will I need a second graphics card for 4k? anything else i need? Is this cooling enough for the cpu and is it still enough to overclock it? Is 850watt power supply enough to run a second graphics card and have the system overclocked? does this motherboard have all the necessary specs and ports for everything on this build?

The Build: https://pcpartpicker.com/list/d63sFd

Component Selection Base Promo Shipping Tax Price

CPU Intel - Core i7-7700K 4.2GHz Quad-Core Processor $329.49 $329.49

CPU Cooler Corsair - H100i v2 70.7 CFM Liquid CPU Cooler $104.99 -$10.00 FREE $94.99 $10.00 mail-in rebate

Motherboard Asus - MAXIMUS IX HERO ATX LGA1151 Motherboard $213.99 $213.99

Memory Corsair - Vengeance LPX 16GB (2 x 8GB) DDR4-3000 Memory $126.99 Free two-day shipping with Amazon Prime $126.99

Storage Samsung - 960 EVO 500GB M.2-2280 Solid State Drive $219.99 FREE $219.99

Video Card EVGA - GeForce GTX 1080 Ti 11GB SC Black Edition Video Card $719.99 Free two-day shipping with Amazon Prime $719.99

Case Cooler Master - MasterCase Pro 5 ATX Mid Tower Case $108.83 Free two-day shipping with Amazon Prime $108.83

Power Supply EVGA - SuperNOVA G2 850W 80+ Gold Certified Fully-Modular ATX Power Supply $140.49 -$20.00 $120.49 $20.00 mail-in rebate

Optical Drive Asus - DRW-24B1ST/BLK/B/AS DVD/CD Writer $18.69 $18.69

Monitor Asus - ROG SWIFT PG278QR 27.0" 2560x1440 144Hz Monitor $625.63 Free two-day shipping with Amazon Prime $625.63 Keyboard Corsair - K95 RGB PLATINUM Wired Gaming Keyboard $170.99 Free two-day shipping with Amazon Prime $170.99

Mouse Razer - DeathAdder Elite Wired Optical Mouse $59.99 Free two-day shipping with Amazon Prime $59.99

Base Total: $2840.06 Mail-in Rebates: -$30.00 Total: $2810.06