I'm going to have a BA done soon with "dual plane" and am having a hard time deciding between 250cc moderate classic and 275cc mod+. Both fit the "12cm" diameter measurements. My ribs are 30" around and each breast is roughly 12cm. I am starting with a 34 deflated b and am hoping to remain pretty small with the least amount of upper breast. I have slight droop from breast feeding, but do not need a lift. Is there a big difference between the two sizes I mentioned? Best for conservative increase?