Hoodies could be done too, but the colors are much more limited in those than long or short sleeve t-shirts. The only green available in the hoodies is Forest Green...which I personally like, but it's not a real popular color of green over all.
The best way to keep cost down is to limit it to maybe two shirt colors and two print colors. The shirt color is not a big limiting factor, but the print color is as there is a fee for every time the color of the ink has to be changed during the printing process. Maybe a Green shirt with Tan print & a Tan shirt with Green print.
The key points here are, this will have to be a pre-paid ordering process and we must have a minimum of 24 shirts ordered to even make it happen.