Depending on where you are you might have a real hobby shop near you, specializing in R/C, Models, Trains. Not like Michaels or Hobby Lobby.
In a good Hobby shop you'll find Tamiya, Testors (Colors by Boyd, Model Master) etc. They have tons of colors, metallics, chromes.
In modeling paints, doesn't matter much what goes though the brush, as long as you dilute it right. Some bottles will tell you the mixture and what to use to dilute. typically you paint thinner on enamels and with acrylics use distilled water