Great idea. Nice design. It'll be a little pricey to print one-offs, but I think this idea is more for the DF fans who would have bought one of Z's t-shirts for the price of two sweatshirts just to have a souvenir.
If Z had this figured out, he'd be selling shirts. Maybe he didn't envision enough orders to justify the effort and investment. Personally, I see it as a good way to monetize his app's brand, but it's easy to say that when it's not my own bucks.
Anyway Whip, count on an order for one large, in black.
Oh, as for format and customization, you might want to consider us squadless types. Maybe on mine, use The Jolly Roger where a squad name goes.
Manfred