Well, for our web-services server, stock Ubuntu Server and a 50 line script does the trick. I have one tarball that I scp over, and it handles setting up accounts, installing the right packages, applying a config-files diff, setting up rc.local and starting the web-services.

I'm planning on setting it up eventually so that it'll automatically clone from the most recent backup of our databases.

I wish there existed, and looked for, tools to manage such a roll-out, but really, it was only a few hours of work to get everything set up. VMWare is your friend there for testing the script, fixing, rolling back to the fresh-installed point, wash, rinse, repeat.