Not completely self hosted. Searxng is just a front end for a bunch of other engines, so it fetches results from google et al. Its good but glitches a lot as the engines themselves try to block it.

Yacy is self hosted, it crawls the sites you tell it to.

The LLMs are great. You can self host the models or just link to the hugging face API. The models you can find there are tuned for specific purposes and are far superior for those purposes. You can also train “agents” on top of those models, like upload your policy and procedure manual and ask it to create additional procedures in that context.