One of the objections some organizations have against using open source tools like Munki is that they want to pay for professional training and support.
Amsys has professional training for Munki:
http://www.amsys.co.uk/amsys-training-courses/coursebooker/munki-101/
If you can’t get to London, check out other professional support and training organizations around the world:
Managing OS X 