I founded a company working to help companies use AI to organize their private knowledge. We have focused on semantic search and knowledge graphs, but we started integrating a chatbot last week and it seems a short leap from where we are.

https://www.summitlabs.ai/

We'd be happy to help implement something. You'll certainly want an embedding database. The open models are getting pretty good, but you'll want to stand up a testing framework. I have a reasonably good model running on a desktop machine in my office with a reasonably priced consumer grade nvidia GPU.

We also have some tactics and practices around hallucination prevention that we'd be happy to share. Feel free to reach out: human at summitlabs.ai