trying to bulid new pc. how will this hold up for 144hz/120hz 1080p gaming?

Solution
MB is not suitable since it can not overclock but 8700k can.
If only gaming, this is my take:

PCPartPicker part list / Price breakdown by merchant

CPU: Intel - Core i5-9600K 3.7 GHz 6-Core Processor ($249.99 @ Walmart)
CPU Cooler: CRYORIG - H5 Universal 65 CFM CPU Cooler ($69.89 @ OutletPC)
Motherboard: ASRock - Z390 Extreme4 ATX LGA1151 Motherboard ($173.88 @ OutletPC)
Memory: Team - Vulcan 16 GB (2 x 8 GB) DDR4-3000 Memory ($99.99 @ Newegg Business)
Storage: Samsung - 860 Evo 500 GB 2.5" Solid State Drive ($72.00 @ Newegg Business)
Storage: Western Digital - Caviar Blue 1 TB 3.5" 7200RPM Internal Hard Drive ($44.89 @...
MB is not suitable since it can not overclock but 8700k can.
If only gaming, this is my take:

PCPartPicker part list / Price breakdown by merchant

CPU: Intel - Core i5-9600K 3.7 GHz 6-Core Processor ($249.99 @ Walmart)
CPU Cooler: CRYORIG - H5 Universal 65 CFM CPU Cooler ($69.89 @ OutletPC)
Motherboard: ASRock - Z390 Extreme4 ATX LGA1151 Motherboard ($173.88 @ OutletPC)
Memory: Team - Vulcan 16 GB (2 x 8 GB) DDR4-3000 Memory ($99.99 @ Newegg Business)
Storage: Samsung - 860 Evo 500 GB 2.5" Solid State Drive ($72.00 @ Newegg Business)
Storage: Western Digital - Caviar Blue 1 TB 3.5" 7200RPM Internal Hard Drive ($44.89 @ OutletPC)
Video Card: EVGA - GeForce RTX 2080 8 GB Black Video Card ($698.99 @ SuperBiiz)
Case: Phanteks - Eclipse P350X (Black) ATX Mid Tower Case ($65.98 @ Newegg)
Power Supply: EVGA - SuperNOVA G2 750 W 80+ Gold Certified Fully-Modular ATX Power Supply ($59.99 @ B&H)
Operating System: Microsoft - Windows 10 Home OEM 64-bit ($98.89 @ OutletPC)
Total: $1634.49
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2019-01-02 15:46 EST-0500
 
Solution