Thank you for the hints. I had a look at the Kobo line and really like the design of the Libra but there is no stylus for it. Did not find an other model with a large screen and stylus.
I saw a BQ Cervantes but it had a 6" screen. Maybe the Pocketbook Inkpad 3 or X come close to what I'm looking for. I would not buy Onyx Boox because once they used Linux-GPL stuff and never released the source code. That's a shame.
I used to have an irex iliad but the display stopped working on two devices and did not buy a third one.

Kobo Clara HD and Tolino Shine 3 are probably same HW, Kobo is Linux based and Tolino has Android so maybe SailfishOS could be ported on these devices.