I had the same sort of idea. I built this when Notational Velocity broke when upgrading to the latest macOS: https://github.com/JesseAldridge/toothbrush It's a single python file for grepping a directory of text files as I type. I have a global keyboard shortcut cmd+J that gives focus to my terminal and I then launch the script by running `t`. Then I can just start typing to search a career's worth of notes.

Would be cool if you could share your setup on GitHub.