Gaming PC for games and live streaming

• Which Precision? Is Full HD (1920×1080) or WQHD (2560×1440) enough or should it be 4K Ultra HD (3840×2160)? The best of this budget
• Ultra/high/medium/low graphics settings? … – super
• 30 Is it enough for you? FPS Or should it be 60 or even 144 fps? …. – It must be at least 60

2. Would you like to use your computer to edit photos/music/videos or CAD? As a hobby or are you a professional? What software will you use?
For streaming, OBS

3. Do you have special requirements or wishes (overclocking, a particularly quiet PC, RGB lighting, …)?
It should be calm, the rest does not matter,

4. How many screens do you want to use? Number, Model, Resolution, Refresh Rate (Hertz)? Do you support FreeSync (AMD) or G-Sync (Nvidia)? (Please with a link to the manufacturer or compare prices!)
I currently have these two screens. Both support Nvidia. Acer Predator XB271HU And Asus VG248QE

5. Do you still have an old computer, parts of which can be reused? (Please with links to specifications from the manufacturer or compare prices!)
no

6. How much money do you want to spend?
3000-4000 Euro

7. When do you want to buy the computer? ASAP or can you wait a few more weeks/months?
Depends on.

8. Do you want to assemble the computer yourself or assemble it (by the store or by volunteers)?
Build it yourself. Just like the last 3 pieces.

PC should allow simultaneous gaming and live streaming in good quality.

Thank you very much for your help.