if you go to zazzle.com you can order plain pet t-shirts on there and then put your logos on them people will have to order them from the site but you get a percentage of it and i think you get to pick the percentage. worth a look i guess.
I know who can make a shirt with your cat on it.
My friend made all Cleo show stuff and she can make jackets,shirts or what ever you want.
If you want I will email her for you.
Just tell me exactly what you would want.