Most of the karate clubs or schools have such a policy. In my opinion, uniform play a main role in focusing your mind. It is a part of putting yourself in a different mind space. It doesn’t care whatever background you are from, it will help you to concentrate on the karate if you are in a uniform. This is what I feel personally. There are many martial arts stores out there in Ontario that provides branded accessories. Hatashita International at Waterloo is the one which I know.