10 Deep, probably the most well known of the "underground" street labels, is coming out with a few New Era caps for fall. Look for them at at all 10 Deep retailers come fall. These will most likely sell out in a few days.
Snap Backs have been around for a long time. Much longer than fitted hats for sure. However, fitted hats have dominated the hat landscape (lol) for years now. Maybe that's why snap backs have started to make somewhat of a comeback. Go cop your snap back at your local Lids or Hat World, but if you want a flat brim, your best bet is to look online. New Era makes a few flat brim snap backs, but they are few and far between.