I got it from a company called Cartoon Colour - they make the stuff right there, so they can mix any color you can think of. They're located in Culver City, CA on Linblade St. I think they might have a website these days - do a search.
It covers quite well since it's primarily used for painting onto clear plastic. Instead of brushing it on, you "puddle" it on with the paintbrush - just as you would if you were painting cels (it flattens somewhat as it dries). While one coat works, two coats are better. I puddle it on with a flatbrush instead of a round - keeps the paint from drying bumpy.