Sounds like Danswer might just fit your needs. Also ya, we came up with this idea of chatting with documents that you can select on the fly, I think we're the only ones who do this still. People have really been liking that one!
If you happen to want to talk to us about Danswer, we'd love to welcome you to our Slack: https://join.slack.com/t/danswer/shared_invite/zt-2afut44lv-...