Acutally there is only one version of FreeBSD. FreeBSD. There are several different ways to install it though. The easiest would be to just download or buy a copy, and install the OS from pre-compiled packages. It functions some of the same way Linux does, but its also a bit different. It is a heckuva lot more stable, but hardware support is not the greatest. FreeBSD would be a great OS if you're looking to run it as a server. If/when you get your box up, LMK and I'll be happy to help you with any problems you encounter.