We use http://www.buckwholesale.com
as a wholesale supplier for merch items. They are not the best in quality, but they are serviceable, cheap, and reliable (not quite Supreme quality, maybe closer to Obey/Urban Outfitters).
A quick search on the site turns this
up - a two-tone cuffed beanie with pom-pom, like you are looking for. I'm sure they have other color combinations.