You can get a 2600 for a really good price and it will have enough threads to game and stream. I would probably wait till the 2060's come out because they will be perfect for a 1k build or I would up your budget to $1100 and go with a 2070. But I put in a 1070 for now as that will be more than enough for CSGO.
PCPartPicker part list:
https://pcpartpicker.com/list/WtNKQZ
Price breakdown by merchant: https://pcpartpicker.com/list/WtNKQZ/by_merchant/
CPU: AMD - Ryzen 5 2600 3.4 GHz 6-Core Processor ($164.99 @ Amazon)
Motherboard: MSI - B450 TOMAHAWK ATX AM4 Motherboard ($114.99 @ Amazon)
Memory: Corsair - Vengeance RGB 16 GB (2 x 8 GB) DDR4-3200 Memory ($129.99 @ Amazon)
Storage: Crucial - MX500 500 GB 2.5" Solid State Drive ($67.89 @ OutletPC)
Video Card: Gigabyte - GeForce GTX 1070 8 GB Windforce OC Video Card ($299.99 @ Newegg)
Case: NZXT - H500 (Black/Red) ATX Mid Tower Case ($69.99 @ Amazon)
Power Supply: EVGA - SuperNOVA G3 650 W 80+ Gold Certified Fully-Modular ATX Power Supply ($59.89 @ OutletPC)
Total: $907.73
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2019-01-14 16:34 EST-0500