Ahoy Stang,
One of my painting rigs has a regulator only. The moisture trap is located in-line, in the hose that goes from the regulator to the airbrush. These in-line traps can be bought separately: Micro Mark sells them, Badger makes one, and Paasche hoses can be bought with or without them. They work quite well.
When you get your rig, blast away and enjoy your painting.
Tom
Tom