need major help with something for March of Dimes

So my whole family walks in honor of my nephew that was stillborn. This years theme for our team is superheroes. We wanna do a shirt that has a superheroe capes attracted to it and have our saying on the cape part. Does anyone know a company that I can order these shirts from? I've looked to the point my head hurts. Any advice on who to contact is greatly appreciated. Thanks in advance.