When we reviewed the new Ryzen 5 3600 we had plenty of positive things to say about it, and that was comparing it to the more expensive...
The R5 is a bit more expensive but B450 motherboards are a bit cheaper, so it works out the same sort of price.
You could also get the RX 5700 XT GPU for only a few € more than the 2070, and the 5700 XT is more powerful overall. To be honest, a graphics card of this level (RTX 2060 Super / 2070 / 5700 XT, etc) is overkill for 1080p gaming. You could just drop to an RTX 2060, which is still very powerful for 1080p gaming, and is ~100€ less.
For the monitor, I strongly suggest getting a monitor with adaptive sync.
I would really recommend a case with better airflow / cooling. It is hard to find something budget that still performs well, but perhaps the Fractal Define S is not too expensive.
Part of the extra expense you can get back by sticking with the stock AMD cooler.