I wouldnt necessarily go with the normal dress size you are (can vary so much from place to place), go by the measurements given on this item they are spot on. The chest line is slightly elasticated so there is some give there but you can hardly tell when its on. Although the dress doesnt come with the hell bunny petticoat, the skirt is 2 layered. The bottom layer has netting giving the effect at the bottom of the skirt and adds volume. Personally the dress has enough volume without the additional petticoat.
This dress has great lines and structure. All you need is a good neckline, the dress will do the rest. It is fitted in the waist, is so flattering on the bust and hides all matter of sins below the waist line. Best bit is that it is so comfortable.