You are in China, which is both a difficulty and an advantage. Most of the devices are made there and can be had at prices much lower than the rest of the world pays. However, what you get might be exactly the same as what is exported.
As for "full distro": I am not sure what that means. You need the ability to install apps. You probably want the ability to change the launcher. Both of these come with any version of Android I know of, but it is possible that the manufacturer has hidden the settings necessary to allow apps and to change the launcher. I like to have the Google Play store but it isn't absolutely necessary, and in any event can usually be added later.
There was a recent thread from DoctorOhh about e-ink readers:
https://www.mobileread.com/forums/sh...d.php?t=285791
As for "do they work": I am satisfied with the two I have. I run the Nova launcher and moon+ reader on both my devices. I don't do other apps such as calendar, email, or web browsing. I get around a 5 days of battery life, the screens are readable, and networking works. CC has a special option to change its animations and colors to be more suitable for e-ink devices.