You could purchase the T-shirts yourself from Wal-Mart or Target and then print your logo or design on a special iron-on transfer paper and print it right from your PC.
Then you take the paper and iron the design onto the T-shirt yourself.
http://www.walmart.com/ip/Epson-Iron....5-x11/4858118
I do this with photographs of the DCK's. I put their pictures on white pillow cases and that way each child knows which pillow is theirs for rest time.
HTH
