Straight up porting an app from Rails to Node.JS seems like a bad idea to me. Not that I'd ever consider using node.js, but the whole appeal is that you can quickly build small services, with either an integrating endpoint or a straight up api in front. If you're just replicating your Rails monolith you forfeit all the benefits.

To be clear instead of node I would consider either Ruby because it is more comfortable, or golang for it's simplicity and performance.