^ Yep, I'd advise holding off too, the release date is 19th so it's only a couple of days more.
A question about your linked build:
PCPartPicker part list /
Price breakdown by merchant
CPU: AMD - Ryzen 5 1600 3.2GHz 6-Core Processor ($174.88 @ OutletPC)
Motherboard: Asus - STRIX B350-F GAMING ATX AM4 Motherboard ($89.89 @ OutletPC)
Memory: Corsair - Vengeance RGB 16GB (2 x 8GB) DDR4-2666 Memory ($184.99 @ Newegg Business)
Storage: SanDisk - Ultra 3D 500GB 2.5" Solid State Drive ($119.99 @ B&H)
Storage: Samsung - 860 Evo 500GB M.2-2280 Solid State Drive ($169.89 @ OutletPC)
Case: NZXT - S340 Elite (Black) ATX Mid Tower Case ($79.99 @ B&H)
Power Supply: SeaSonic - FOCUS Plus Gold 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($54.99 @ Newegg)
Total: $874.62
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-04-17 13:02 EDT-0400
Why two SSD drives? a single <> 1Tb SATAIII drive would be cheaper and you'd barely notice the difference in performance ( unless you do a LOT of drive intensive work that is ).
One thing that has not yet been mentioned is the monitor/s you'll be using, or the games you'll be playing, to get the best FPS and smoothest play we'll need to know the monitor details before making any suggestions about the GPU.
Monitor choice may also alter our suggestions on the whole build, Intel holds a significant performance advantage on a fast 1080 display for example.