currently we are at a lack of limux experts here. but I can answer your question about the servers. The server only requires you to have Wolfenstein Enemy Territory 2.55 full version (free, you can download here), adn its patch, 2.6, then the latest TCE full install and patch, just like a normal installation of TCE. Other maps are third party addons and they can be aquired from
www.eclipse-esports.com, I may have gotten the link wrong, its in the site somewhere. But, dont bother about 3rd party maps since when the new TCE version comes out, these third party maps are nolonger supported. The requirements to run a server on your own pc while playing are a bit higher, most important thing is a dualcore processor if you plan to host and play on the same machine. Ofcourse more ram as you will be transferring player information back and forth. The best solution to server hosting is to rent a dedicated server. Go to the severs section of the TCE.US forums and ask around for a good deal, someone here may know somewhere you can rent a cheap, but usefull dedicated server.
Your in the right section, you are having trouble with setting up a server, then your in the right place.