Based on your requirements, I would suggest looking at one of the Firefish / CalcKey forks. They are ideal for single user or small instances and they support s3 compatible object storage out of the box.
I would recommend looking at Sharkey or Iceshrimp. Both are under very active development and have very responsive developers if you need support.
If you would like to check out an example, Ruud (of mastodon.world and lemmy.world) set up an instance of Sharkey at (you guessed it) sharkey.world.