Leanpub is easy and works.
I would consider Obsidian for my next venture as Scrivener has too many features for me that I don't need.
For my poem book I wrote some code that generated mazes for the cover [0]
We do go with Amazon for ebooks but not for printing, their quality is way below what we find acceptable (we're in Germany and found a printer in Poland after being let down by our German printer).
[0] https://www.amazon.de/Olavsweg-Gedichte-Gedanken-lyrische-In...