re: Where can I get this shirt?

1) In your link URL in YouTube, add "#t=15m17s" so people don't have to manually jump in your video.

2) It's likely an old shirt that made its ways overseas years ago, and you probably cannot find it in the US. You should read the book The Travels of a T-shirt in the Global Economy for a more detailed explanation of where your T-shirt goes after you drop it off at the Salvation Army donation bin.