I avoided Zookeeper for a long time, due to its apparent complexity, but am now very glad I finally took the plunge. There's a good cloud formation script here (https://github.com/thefactory/cloudformation-zookeeper) I had to open up the load balancer to get a public endpoint like zk.yourdomain.com.

etcd and others are quickly coming onto the scene, but zookeeper is still the right choice if you want full featured, robust software with a good ecosystem of tools & knowledge like Curator, Exhibitor, Cloud Formation, etc...