I have a personal preference for cfengine over puppet, because its way more powerful although being the most versatile and scalable technology of this kind.
You can have an overview of Cfengine 3 here :
Managing configuration with Cfengine 3: concepts & theories Normation Blog
You should also register to their website: you'll find many resources there, including Cfengine (2, 3 and Nova) binary packages for Cfengine for almost every linux distro and unix flavor.
Regards,
Nico