Two inputs here from me.
1. For small touch ups, use the torn end of a paper match as a brush. Of course they're not a commonly available as they once were.
B. Although it's gloss instead of flat, I've been very happy with appliance epoxy paint available in many places including home repair stores. This stuff is tough!
http://www.krylon.com/products/appliance-epoxy/
And if you want to be truly different, go with almond or bisque to stand out from the crowd.
Jay.