I use Montana Gold spray paint on all my cab repaints. It really lays down nicely, and there are a great variety of colors. I believe the finish is semi-gloss. I've selected colors for a Lost World, but haven't ordered yet - Old Safran or Shock Yellow (I'm going back and forth on that one) Gonzo and Fire Red.
Prior repaints, I've made my own stencils using frisket and poster board. An example is in my icon or avatar or whatever you call that thing over there on the left. I'm going to get a set of pimp stencils for this one, though.