my advice for a production enviroment would allmost certianly be to use one of the distributions that has commercial support avalable if you wish to pay for it.
a good example would be SuSE linux (a free version is avalable with no support and a paid for version with world class support (still cheaper than MS))
support in forums like LQ while free is provided by other members of the community, there is a chance that nobody will know the answer to any question you post in the time you need it in.
practically all of us have full time jobs an dare not paied to answer questions here
other than that i would definatly advise that you get a spare computer, install linux... try using it as a server form a few windows hosts that arnt essential if they have any bugs.... then when you are happy that everything is working roll out to the production enviroment.