I like to use Testors brand Acrylic model paint, those used one model cars and planes. The acrylic is very important, you do not want to use enamel (enamel is oil based) on ponies. Though any acrylic paint works pretty well, I've found that the model paints are less likely to get clumpy or streaky, you don't need to water them down, and you usually need only one to two coats for a symbol.
I've seen alot of different answers for what sealer to use but I go by this general rule of thumb, use the same brand of sealer as the brand of paint you use. This is because each brand has their own formula and they have sealers that work the best with their paint, they won't react badly to the paint and cause stickyness or other unwanted stuff.
