I forgot to mention that the server package is only necessary if you plan on letting people play on your map when you're not on, or if you want a machine other than the one you're running the game from to host the map. If it's only going to be accessible when you're in-game and you don't need an additional computer in the mix, then just the client will do (you can launch the map into a mini server straight from the local tab in the game client - just keep in mind that said mini server shuts down when you exit out of the game).