PocketBooks⁴ look interesting, especially in the colour e-ink offers⁵ but I can’t personally attest to that.
Take a look at the Good e-Reader website⁶ for reviews of several brands and models.
² https://pgaskin.net/kepubify/
³ Though you don’t have to; unconverted EPUBs load fine.
⁵ https://www.theverge.com/21507390/pocketbook-color-review-e-...
Recently I decided to try a Kindle Scribe and I'm now completely taken by it. There's something so much nicer about reading on an eInk screen that's approximately the size of a real printed page.
I only use the scribe for reading, though I may try using it for notes when the software improves. I don't really care about that through. In any case, I find myself reading much more than I used to. It's not water proof though, so I probably won't take it to the beach.