Streaming & Video Editing PC for 800-900 euro?

I would like to set up a PC setup in the near future which is primarily suitable for editing 4K video material and for streaming on Twitch. It would be ideal if the PC can stream and games can be played on FULL HD in the stream at the same time. I'm aware that a PC that is streaming and gaming at the same time needs a lot more power. Is it even possible to find something useful with such a budget? I think it's more sensible to assemble a PC myself, but unfortunately I don't have the necessary know-how, so it will probably have to be a finished PC. Can you recommend some good sites that have a good price / performance ratio? As I said, I'm aware that I will not get a Monster PC here, but at least one on which video editing and streaming runs smoothly would be important to me.

I did a little research in advance and concentrated on the following hardware that might come into question. (At MIFCOM I once configured a similar one, but somehow I have the feeling that the prices there are sometimes really very high)

Processor: AMD Ryzen 5 3600

GPU: NVIDIA RTX2060 or AMD RX 5700XT

RAM: 16GB DDR4

With the mainboard I'm not sure which one would be the right one, I would be happy if someone could be found here who can help me. This is of course just my rough idea, it can also be that this is complete nonsense. Looking forward to your replies.

PS: The optics of the PC are of secondary importance to me, prefer good hardware and save on optics.

I can recommend Shadow Tech, check out what that is.

https://www.rhino-computer.de/index.php

They make very good PCS.

I would definitely recommend more RAM for editing 4K material. I myself use 64 GB from Corsair and they almost reach the limit when cutting, especially when there are a lot of overlays.