My LHS stocks Humbrol Enamels & Acrylics, Testors Enamels, Testors Model Master Enamels & Acrylics & Tamiya Acrylics, along with Testors and Tamiya Rattle Cans. From my own observation the armor guys buy MM & Humbrol Enamels, the aircraft guys buy Tamiya and MM Acrylics, and the car guys buy the rattle cans and a mix of the others. No-one seems to buy the Humbrol Acrylics and the rack is looking pretty bare these days.
Squadron carries the Humbrol line, though I don't know if they carry both enamels and acrylics. Great Model carries only the enamels.
Why do you want to buy a paint that seems to be hard for you to get?