For all intents, without counting the e-note or color
or water-resistance aspects, you're looking for a 10" e-reader--the sizes jump from 8" straight to 9.7"/10"/10.3" and then up--for $300-ish. And there is one non-Kindle e-reader in that price range: the
PocketBook InkPad Lite. So you're basically looking at something used, or stretching your budget, unless you get lucky and find a deal on something like a first-gen
Kobo Elipsa or a
Meebook P10 Pro or, if you really want to get old, an
Onyx Boox N96/N96ML.
And it probably must be said: color is right out at this point, especially at that size range, unless a literal unicorn drops one in your lap.