The litephone is too basic and the HiSense A5 etc do not work on US networks.
I looked at building a 5.2" e-ink phone for the US market and did some fun mock-ups, but it would be a huge undertaking with my limited hardware background. Smaller phones just have fundamental limits due to battery size that are difficult to work around, and Android has basically no e-ink support as it's such a niche type of display for a phone.