Run npm Enterprise on AWS with just a few clicks
blog.npmjs.org
blog.npmjs.org
We should look at ECS though. Are you more likely to deploy if something is in ECS than if it's a straight AMI?
Though I must admit (1) I am not one of your customers, and (2) our BAA with Amazon prevents us from using ECS. We typically run node on ebs backed m3.medium instances running Amazon Linux.