I did some research, I found a site. There is a site online called giantvintage.com. Or you can just google "Giant Vintage Sunglasses". They have some big style sunglasses that are cheap and stylish.
Guys and girls can check this site out. They have a whole bunch of styles that are big. I got some and they fit fine.
Oakleys makes a pair for big heads
Lamood is a specialty online store that has sunglasses as well as hats for big heads http://www.lamoodbighats.com