Is the venue where you'll be selling your products odor-free? One thing I've noticed about baked goods (especially breads) is that they absorb odors very easily. If there's any chance that your products will be in an odorous environment (coffee, smoke, perfume, cleaning products, fish, cooking odors) I would recommend heavy duty packaging. Plastic is both air and odor permeable. If you have to use plastic, the thicker the better. Double bagging might help.
Also, if you know your goods will be frozen, thicker plastic/less air in the bag will be a preventative for freezer burn.
And lastly, make sure the plastic itself doesn't have a smell that will taint the food. Although I'm more sensitive than most people, I can detect the off flavor in zip lock bag stored food.