Is this a good idea?
I'd think of it this way. Yes, this is a use case well-suited to node.js's strengths.
what modules do you recommend for such a purpose?
- app server: express.js
- web sockets: socket.io (maybe socks.js)
- HTTP from gateway to back end: hyperrequest or superagent or request.js
- if you need any straight-up HTTP proxy functionality: node-proxy