Komodo Edit (free to use) and Komodo IDE (requires paid license) support syntax highlighting for JavaScript and CoffeeScript. I believe call hints for node.js are provided.
http://www.activestate.com/komodo-edit
http://www.activestate.com/komodo-ide
I can vouch for KomodoEdit as a good IDE in general; I've been using it in Python and PHP projects with satisfaction.
Be sure to start with the 7.0 release candidate; it's been RC for quite a while, and you could miss it if you start from the Komodo Edit home page. 6.0 is probably before CoffeeScript became popular.
