Future proof gets expensive and 600-800 is not a big budget.
Here is Intel:
PCPartPicker part list:
https://pcpartpicker.com/list/Wc8VGG
Price breakdown by merchant: https://pcpartpicker.com/list/Wc8VGG/by_merchant/
CPU: Intel - Core i5-8400 2.8GHz 6-Core Processor ($195.79 @ OutletPC)
Motherboard: Gigabyte - B360M DS3H Micro ATX LGA1151 Motherboard ($65.99 @ SuperBiiz)
Memory: G.Skill - Ripjaws 4 Series 8GB (2 x 4GB) DDR4-2666 Memory ($80.98 @ Newegg Business)
Storage: Kingston - A400 240GB 2.5" Solid State Drive ($54.89 @ OutletPC)
Video Card: Gigabyte - GeForce GTX 1070 8GB Windforce OC Video Card ($399.99 @ Newegg)
Total: $797.64
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-08-06 10:03 EDT-0400
Here is AMD:
PCPartPicker part list:
https://pcpartpicker.com/list/njdkgw
Price breakdown by merchant: https://pcpartpicker.com/list/njdkgw/by_merchant/
CPU: AMD - Ryzen 5 2600 3.4GHz 6-Core Processor ($165.99 @ Amazon)
Motherboard: ASRock - B450 Pro4 ATX AM4 Motherboard ($91.98 @ Newegg)
Memory: G.Skill - Ripjaws V Series 8GB (2 x 4GB) DDR4-3200 Memory ($94.99 @ Newegg)
Storage: Kingston - A400 240GB 2.5" Solid State Drive ($54.89 @ OutletPC)
Video Card: Gigabyte - GeForce GTX 1070 8GB Windforce OC Video Card ($399.99 @ Newegg)
Total: $807.84
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-08-06 10:04 EDT-0400
While the 8400 has slightly better gaming performance (5%ish) than the 2600, the 2600 has twice as many threads that will help with multitasking. I would go with the 2600 just because you get more CPU for the money.