These are best in stainless steel - and come in a set of graduated sizes (from 1/4 cup to 2 cups). Straight rims allow ingredients to be leveled in the cup for accuracy. Plastic measuring cups are cheaper - but they are also less accurate - and less sturdy. That said - plastic will work - and if you must economize - this is one place you can do it!
Can any good brand of chocolate be used for dipping strawberries and still set up hard when cool? If not, can anything be done to it or added to the melted chocolate to ensure it will set up hard to the touch?