The point of curing is to dry your buds out as slowly as possible without having them start molding; drying them out fast isn't the way to go unless you're in a hurry or your buds are just how you like them.

Plastic allows air to pass through it, albeit slowly, so it's not the best choice for long-term storage. Glass and metal are the best choices. Are you sure you can't just get a few pickle jars? Anyway, if you do use bags, freezer bags are better than sandwich bags. Cold cereal bags are pretty thick too, and foil bags are the best.