If you can get one of the early Kobo ereaders, you can flash this Libre OS on it, that would be better.
Also, those early Kobo ereaders (glo, nia, mini and some other models) can support up to 32gb sdcard, that’s a lot of books and out goes the need for cloud storage
i’ve been desperately trying to get my hands on one of those, but I live in a third country and import duties are a pain