Ubuntu's repositories always seem to be a few packages behind for Redis and Node.js (and probably many others). Luckily Chris Lea maintains PPA repositories with the latest stable versions of Redis and Node.js.

Node.js: https://launchpad.net/~chris-lea/+archive/node.js/
Redis: https://launchpad.net/~chris-lea/+archive/redis-server

Adding them to the computer for use just involves running
sudo apt-add-repository ppa:chris-lea/nodejs for Node.js, and
sudo apt-add-repository ppa:chris-lea/redis-server for Redis.