Budget: ~2000
Resolution: Hopefully 1440p
Games / Settings Desired: Rainbow Six Siege, League of Legends, Playerunkown's Battlegound.
Any other intensive software or special things you do (Frequent video encoding, 3D modeling, etc): No
Country: United States
Parts that can be reused: Power supply
Do you need an OS?: Yes
Do you need peripherals (e.g. monitor, mouse, keyboard, speakers, etc)?: 1440p Monitor

Parts:
CPU: Intel - Core i7-6700K 4.0GHz Quad-Core Processor
CPU Cooler: NZXT - Kraken X62 Liquid CPU Cooler
Motherboard: MSI - Z170A SLI ATX LGA1151 Motherboard
Memory: Corsair - Vengeance LPX 16GB (2 x 8GB) DDR4-3200 Memory
Video Card: EVGA - GeForce GTX 1070 8GB SC Gaming ACX 3.0 Video Card
Case: NZXT - S340 Elite (Black/Red) ATX Mid Tower Case

This is the part list I have put together. I already have the motherboard, memory, ssd, and case. Would it be worth it to buy a 1080 Ti instead of 1070? And is the liquid cpu cooler a good cooler to buy?