Sorry, but just to confirm, are you asking for a GPU that is good for under 100 Euros? Or perhaps there was a typo to keep the system cost under 1000? If that was indeed what you typed, I would advise staying away from GPU's below that price range. They are NOT worth their price. You could EASILY get better performance with the Ryzen 5 2400G. Just confirm with the seller of the motherboard that it is guaranteed to be compatible with the 2400G out of the box. Otherwise, you might have to contact a local PC shop and have them do a BIOS update (or use AMD's boot kit program). You can also save quite a bit of money by going for less flashy RAM.
This config keeps the high quality RAM, but allows you to expand to a 240GB SSD AND a 2TB HDD for only 10 Euros more.
EDIT: Fixing config.