I don't think a minimalist is attached by one certain brand of product or service. Everyone has their own taste and compatibility with brands, which is okay.
The point is simply how the product and/ or service can bring joy, happiness, and add values for you.
Fumio Sasaki, author of Good Bye Things, stated very clearly that he is a huge fan of Apple products. He use Iphone and Macbook Air. So, should you use all of Apple's product to become a minimalist like him?
Of course not. You could use Apple's if you want to. However, it has nothing to do with becoming a minimalist.
Becoming a minimalist is simply live with only things that add values for you, no matter what the brand is.
So, if you ask me what brand should you use or wear, my answer would be wear any brands that makes you happy.
Becoming a minimalist is more than just choosing brand. It's about live with more intention and awareness.