I've been working on a web app for a small charity in my spare time, and when it came to server set up we had a debate about whether Chef or Puppet would be too

I've been working on a web app for a small charity in my spare time, and when it came to server set up we had a debate about whether Chef or Puppet would be too much for what will likely be a single production server (currently EC2) for a long time. Does anyone have experience running this kind of tool with a single server? Is it worth it? What if we added a staging server too?