But is it goood enough for price 1100€?You shouldn't upgrade anything.
I already have a 1080 and im buying other partsI wouldn't buy this mix of parts. It maybe a good value on an individual parts basis, but they don't fit well.
3900 is overkill, 16 gig of ram is plenty, waste of money for 32, 1080 is a great card, but 2060, 2070 or 5700xt are better cheaper cards right now.
I already have a 1080 and im buying other parts
I have an MSI mag272c 165HzSo you have a budget of 1100 euro for a system sans GPU. Where are you located, what monitor resolution / refresh rate are using?