I stenciled a room a couple of months ago and I used a metallic paint from Martha Stewart's paint line from Home Depot. The room came out great if I do say so myself. At the time, the paint was only available in quart cans and was fairly expensive for a quart of paint, the bummer was I only used 1/4 of the can.
I'm now planning to stencil my powder room and headed to Home Depot for more paint, because of course I needed a different color. I was pleasantly surprised to find that the metallic paint is now being sold in 8 oz jars and only for $5.48. SCORE! So if you're looking for metallic paint for a small project, head on over to Home Depot.