Ubuntu has a backports repository which would be an appropriate venue for the latest and greatest of nginx, phusion passenger, etc.
What with package signing, having an HTTPS repo is kind of pointless.
We run Graphite (a Django app) on Phusion Passenger on our internal servers.
By the way, we open source Node.js support in 4.0.16. Previously it was only available in the Enterprise variant. You can learn more at https://github.com/phusion/passenger/wiki/Node.js