I am a 34 yr. old woman, 155 lbs, medium frame, and my current bra size is 36D. I am indecisive about selecting a 400ccL/450ccR or a 450ccL/500ccR.
I have tried on the sizers and liked both. However, I am afraid that if I go with the 450/500 it will look to big. I want my breast to have a full feeling but do not want them to be too big.
A: breast implants and a lift
Looking at your photo, it seems that you may also need a breast lift at the same time of your breast implant insertion. The sizes you list (400-500cc) are fairly large and may get you to the cup size you want however these implants may over time cause your nipple position to drop. This is difficult to determine without examining you in person, but you may want to consult with one or more board certified plastic surgeons in order to see what the best approach is for your particular anatomy.