From your specs it's better to start new.
PCPartPicker part list:
https://pcpartpicker.com/list/ZzZwcY
Price breakdown by merchant: https://pcpartpicker.com/list/ZzZwcY/by_merchant/
CPU: Intel - Core i5-8400 2.8GHz 6-Core Processor ($178.89 @ OutletPC)
Motherboard: Gigabyte - B360 HD3 ATX LGA1151 Motherboard ($83.24 @ Amazon)
Memory: ADATA - XPG GAMMIX D10 16GB (2 x 8GB) DDR4-2666 Memory ($158.99 @ Newegg)
Storage: SanDisk - SSD PLUS 480GB 2.5" Solid State Drive ($109.99 @ Amazon)
Storage: Seagate - Barracuda 2TB 3.5" 7200RPM Internal Hard Drive ($59.79 @ OutletPC)
Video Card: MSI - GeForce GTX 1060 6GB 6GB GT OCV1 Video Card ($299.99 @ Amazon)
Case: Phanteks - Eclipse P300 Tempered Glass ATX Mid Tower Case ($49.99 @ Newegg)
Power Supply: SeaSonic - 520W 80+ Bronze Certified Fully-Modular ATX Power Supply ($49.99 @ SuperBiiz)
Total: $990.87
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-05-09 14:25 EDT-0400
Or
Drop ssd and 1 ram stick for more gaming power, buy the 2nd ram stick + ssd later
PCPartPicker part list:
https://pcpartpicker.com/list/bYW4sZ
Price breakdown by merchant: https://pcpartpicker.com/list/bYW4sZ/by_merchant/
CPU: Intel - Core i5-8400 2.8GHz 6-Core Processor ($178.89 @ OutletPC)
Motherboard: Gigabyte - B360 HD3 ATX LGA1151 Motherboard ($83.24 @ Amazon)
Memory: Crucial - Sport LT 8GB (1 x 8GB) DDR4-2666 Memory ($82.84 @ Amazon)
Storage: Seagate - Barracuda 2TB 3.5" 7200RPM Internal Hard Drive ($59.79 @ OutletPC)
Video Card: MSI - GeForce GTX 1070 Ti 8GB DUKE Video Card ($499.99 @ Amazon)
Case: Phanteks - Eclipse P300 Tempered Glass ATX Mid Tower Case ($49.99 @ Newegg)
Power Supply: SeaSonic - 520W 80+ Bronze Certified Fully-Modular ATX Power Supply ($49.99 @ SuperBiiz)
Total: $1004.73
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-05-09 14:28 EDT-0400