Not to large on the logo.
Offer long sleeve and short sleeve T's. Good quality, not too thin.
How about something fun on the back like this? :
I agree, the 50/50 shirts are good quaility. We will come up with some different designs, I really think the MACA logo is bad ass and would look good on the back, big, like the example, but we will decide once we get the logos back. Maybe I will have him do one without the circle in color and B/W and one with the circle, color and b/w, and we can design shirts, hats etc. from there.