DDR4-3200MHz, dual channel kit.
WD SSD's are not my cup of tea, I'd suggest a Samsung 850 Evo.
Are you trying to build under 1,000USD?
PCPartPicker part list /
Price breakdown by merchant
CPU: AMD - Ryzen 5 2600X 3.6GHz 6-Core Processor ($188.99 @ Amazon)
Motherboard: Asus - ROG STRIX X470-I GAMING Mini ITX AM4 Motherboard ($200.99 @ SuperBiiz)
Memory: G.Skill - Ripjaws V Series 16GB (2 x 8GB) DDR4-3200 Memory ($154.99 @ Newegg)
Storage: ADATA - Ultimate SU800 256GB 2.5" Solid State Drive ($57.99 @ Amazon)
Storage: Seagate - Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($37.09 @ Newegg Marketplace)
Video Card: EVGA - GeForce GTX 1050 Ti 4GB FTW GAMING ACX 3.0 Video Card ($209.99 @ Amazon)
Case: Fractal Design - Define Nano S Mini ITX Desktop Case ($59.99 @ SuperBiiz)
Power Supply: EVGA - SuperNOVA G3 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($67.99 @ Newegg)
Total: $978.02
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-07-19 04:24 EDT-0400