Is 550w 80+ gold PSU enough for this build??

Solution
Yes it's plenty of power , but here's a better one. Has a 10 year warranty! :)

PCPartPicker part list / Price breakdown by merchant

CPU: Intel - Core i5-7600K 3.8GHz Quad-Core Processor ($199.89 @ Amazon)
CPU Cooler: Cooler Master - Hyper 212 LED 66.3 CFM Rifle Bearing CPU Cooler ($21.83 @ Amazon)
Motherboard: MSI - Z270 GAMING PLUS ATX LGA1151 Motherboard ($114.89 @ OutletPC)
Memory: Corsair - Vengeance LPX 8GB (2 x 4GB) DDR4-2400 Memory ($102.89 @ OutletPC)
Storage: Kingston - A400 120GB 2.5" Solid State Drive ($57.99 @ Amazon)
Storage: Toshiba - 2TB 3.5" 7200RPM Internal Hard Drive ($61.88 @ OutletPC)...

Dark Lord of Tech

Retired Moderator
Yes it's plenty of power , but here's a better one. Has a 10 year warranty! :)

PCPartPicker part list / Price breakdown by merchant

CPU: Intel - Core i5-7600K 3.8GHz Quad-Core Processor ($199.89 @ Amazon)
CPU Cooler: Cooler Master - Hyper 212 LED 66.3 CFM Rifle Bearing CPU Cooler ($21.83 @ Amazon)
Motherboard: MSI - Z270 GAMING PLUS ATX LGA1151 Motherboard ($114.89 @ OutletPC)
Memory: Corsair - Vengeance LPX 8GB (2 x 4GB) DDR4-2400 Memory ($102.89 @ OutletPC)
Storage: Kingston - A400 120GB 2.5" Solid State Drive ($57.99 @ Amazon)
Storage: Toshiba - 2TB 3.5" 7200RPM Internal Hard Drive ($61.88 @ OutletPC)
Video Card: MSI - Radeon HD 7870 GHz Edition 2GB Video Card
Case: Fractal Design - Define R5 (Black) ATX Mid Tower Case ($99.99 @ SuperBiiz)
Power Supply: SeaSonic - FOCUS Plus Gold 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($54.90 @ Newegg)
Operating System: Microsoft - Windows 10 Home Full 32/64-bit ($109.99 @ B&H)
Wireless Network Adapter: Asus - PCE-AC88 PCI-Express x1 802.11a/b/g/n/ac Wi-Fi Adapter ($108.76 @ Amazon)
Case Fan: Noctua - NF-F12 PWM 55.0 CFM 120mm Fan ($19.50 @ Newegg)
Case Fan: Fractal Design - X2 GP-12 (White) 52.3 CFM 120mm Fan ($8.49 @ SuperBiiz)
Case Fan: Fractal Design - X2 GP-12 (White) 52.3 CFM 120mm Fan ($8.49 @ SuperBiiz)
Fan Controller: NZXT - SENTRY 3 Fan Controller ($32.75 @ OutletPC)
Total: $1002.24
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-11-28 17:02 EST-0500
 
Solution
Yes, but wifi is overkill, for the budget, coffee lake is better and has upgrade path which Kaby lake lacks.

PCPartPicker part list / Price breakdown by merchant

CPU: Intel - Core i5-8600K 3.6GHz 6-Core Processor ($295.99 @ B&H)
CPU Cooler: CRYORIG - H7 49.0 CFM CPU Cooler ($28.90 @ Newegg Marketplace)
Motherboard: MSI - Z370 PC PRO ATX LGA1151 Motherboard ($119.89 @ SuperBiiz)
Memory: Team - Vulcan 16GB (2 x 8GB) DDR4-3000 Memory ($139.99 @ Newegg)
Storage: SanDisk - X400 256GB 2.5" Solid State Drive ($72.50 @ Newegg Marketplace)
Storage: Toshiba - 2TB 3.5" 7200RPM Internal Hard Drive ($61.88 @ OutletPC)
Video Card: MSI - Radeon HD 7870 GHz Edition 2GB Video Card
Case: Fractal Design - Focus G (Black) ATX Mid Tower Case ($39.99 @ SuperBiiz)
Power Supply: SeaSonic - FOCUS Plus Gold 650W 80+ Gold Certified Fully-Modular ATX Power Supply ($69.99 @ SuperBiiz)
Operating System: Microsoft - Windows 10 Home Full 32/64-bit ($109.99 @ B&H)
Wireless Network Adapter: TP-Link - TL-WDN4800 PCI-Express x1 802.11a/b/g/n Wi-Fi Adapter ($34.99 @ Amazon)
Case Fan: Noctua - NF-F12 PWM 55.0 CFM 120mm Fan ($19.50 @ Newegg)
Case Fan: Fractal Design - X2 GP-12 (White) 52.3 CFM 120mm Fan ($8.49 @ SuperBiiz)
Case Fan: Fractal Design - X2 GP-12 (White) 52.3 CFM 120mm Fan ($8.49 @ SuperBiiz)
Fan Controller: NZXT - SENTRY 3 Fan Controller ($32.75 @ OutletPC)
Total: $1043.34
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-11-28 17:18 EST-0500