"Balance" is tricky. There is physical size to consider, but there is also "presence", how much psychological space one takes up, how one "carries" oneself. Whether you a "big woman" or you are a "fat woman" can depend on personality. I am told by experienced fitters that I "need" a bigger bust to match my larger "presence". As in somewhere around DDDD cup (better known as G to the rest of the world.)
I don't know what surgeons will recommend. One calculation I ran through suggested that the maximum my body will hold is about 420 cc. My mental target size is 38DD (= 38E) or perhaps 38DDD (= 38F), with 38D being the absolute least I currently feel would be worth going though. But those targets take me into the 700-750 cc range, far above what my body might support.
