I don't think any of the existing plugins are going the direction I want to go. I want to write as much of this in PHP as possible to make it easier for myself and other PHP developers to contribute to.
I've started a repo at https://github.com/deweller/PHPCodeIntel
There's nothing there yet, but I hope to work up a proof of concept soon.
If you are interested in contributing, follow the repo or email me at firstname.lastname@example.org
and I'll send out some updates.