i bought the 6" display from eink.com to build a small personal art project - an infinite scrolling procedurally generated landscape based on this project - https://github.com/LingDong-/shan-shui-inf

A few gotchas:

1. some of these eink boards are hard to procure as a consumer. the vendors want you to be a company

2. the driver boards are purchased separately, are definitely required, and sometimes have windows software (vs easy to use rasp-pi drivers)

3. support is often difficult or from the OEM so english-language communication can be difficult.