After much exploring, my first technical landscape seems to be built on Minecraft for animation resources. The reason is a couple, Minecraft itself presents minimal graphics, yet people still find it engaging enough to understand body language by virtue of its success on YouTube. Secondly, it has a huge community which has put together a great number of tools.
My tool set is Blender. Blender has a large community and seems the only open source platform that can compete on animation. It’s been around a long time, has a huge user base, so I’m confident it can handle everything I need.
Another question was where I would get audio from. I found a great site called https://librivox.org/, where a bunch of people get together and narrative public domain books, and re-license their work as public domain also.
So, that means altogether I have the model sources, animation tool, and audio source located.