what kind of enamel paint should i use to paint an antique sign?

[qbtom48]

I a fine art student trying to paint an antique style sign. i purchased a piece of sheet metal about 3x4ft and covered it with a black matte primer.....but i was wondering if you could give me any tips. I heard enamel paint is what i need to use, but whats the best brand/where i find it? and how should it be applied...brush?...how many coats? Also, how do you get that antique/aged look? Anything you could tell me would be greatly appreciated. thank you