PCS have a pre-configured "Review" spec that should fit the bill. It's a fixed spec that comes with a discount versus what you'd pay if you manually drew up the same spec.
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R7 3700x will be very capable for streaming (and gaming), while the 2060 Super is very powerful (overkill really) for 1080p gaming. And it has good features like an H100x CPU cooler, TXM PSU, and 970 Evo SSD.