I can ditto the posts of Marcellette and Diane above.
Personally, I have had great success with Feminique products from Amazon (70 dollars). I wear size D which gives me my preferred B / C cup. I describe myself as a plus plus girl (over 6 feet tall, and 300 pounds). I wear my forms full time three years and each pair has lasted me between 12 and 18 months before needing replacement.