Your build is titles "i3-8100"? Just making sure you linked the correct setup?
You're going to want dual-channel memory (2x4GB or 2x8GB) and appropriate speed (3000MHz+) for optimal Ryzen performance if you go that route.
While not a concern with a single GPU like a 1060, opting for an APU is both unnecessary (no need for the iGP) and potentially detrimental for future upgrades. The APUs only have x8 available for a single GPU (I believe) vs a true x16 connection. Current GPUs are not saturating even x8, so might not be a huge concern, but if it all possible, a true CPU would be a better route to go.
Modifying the build somewhat:
PCPartPicker part list /
Price breakdown by merchant
CPU: AMD - Ryzen 5 2600 3.4 GHz 6-Core Processor ($164.99 @ Amazon)
Motherboard: Gigabyte - B450 I AORUS PRO WIFI Mini ITX AM4 Motherboard ($119.99 @ Amazon)
Memory: Team - Vulcan 16 GB (2 x 8 GB) DDR4-3000 Memory ($89.99 @ Newegg Business)
Storage: Crucial - MX500 500 GB M.2-2280 Solid State Drive ($67.99 @ Amazon)
Video Card: PowerColor - Radeon RX 580 8 GB Video Card ($169.99 @ Newegg)
Case: Thermaltake - Core V1 Mini ITX Desktop Case ($44.91 @ Amazon)
Power Supply: EVGA - SuperNOVA G2 650 W 80+ Gold Certified Fully-Modular ATX Power Supply ($59.99 @ B&H)
Total: $717.85
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2019-01-21 16:09 EST-0500
A 580 will trade blows with a 1060 with each card taking a win in certain titles. Pretty similar performance though and, given the 1060 costs ~60% more (after rebates are factored in), it's really tough to justify a 1060 right now.
Gives you a 6c/12t chip, appropraite board and 16GB of RAM.
The 650W G2 is actually cheaper than the 550.
You could switch out the PSU for a CX550 to bring you under $700 (after rebates), but for the money, the G2 is a better quality unit.
PCPartPicker part list /
Price breakdown by merchant
CPU: AMD - Ryzen 5 2600 3.4 GHz 6-Core Processor ($164.99 @ Amazon)
Motherboard: Gigabyte - B450 I AORUS PRO WIFI Mini ITX AM4 Motherboard ($119.99 @ Amazon)
Memory: Team - Vulcan 16 GB (2 x 8 GB) DDR4-3000 Memory ($89.99 @ Newegg Business)
Storage: Crucial - MX500 500 GB M.2-2280 Solid State Drive ($67.99 @ Amazon)
Video Card: PowerColor - Radeon RX 580 8 GB Video Card ($169.99 @ Newegg)
Case: Thermaltake - Core V1 Mini ITX Desktop Case ($44.91 @ Amazon)
Power Supply: Corsair - CX (2017) 550 W 80+ Bronze Certified ATX Power Supply ($31.99 @ Newegg)
Total: $689.85
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2019-01-21 16:09 EST-0500