Thank you for the question.
I would suggest that you communicate your goals (in regards to breast size) clearly/carefully with your plastic surgeon. Generally, I prefer the use of goal pictures to help with this communication given that discussion of cup size can be quite subjective. As you know, breast cup sizes will vary depending on who makes the bra. I would also suggest that you do not base your satisfaction with the results of surgery on achieving a specific cup size.
You are also wise to consider that your abdomen will look smaller after tummy tuck surgery ( and probably with a smaller waistline as well); take this into consideration when discussing your goals with your plastic surgeon.)
Good luck with your upcoming procedures.