Get the curved brim ones since they come in the box with a flat brim anyways, and if the kids want to wear em as a flat brim "straight out the box" then let em. Tag and all. Then break the brim on yours.
Problem solved
They didnt have flat brim hats in the mid 1980s when this homeboy trend started in the inner cities. These kids wore regular ball caps "straight out the box" eventually manufacturers capitalized on this look.