Hi Gidget,
The choice of the right size implant is very important to your final result. I have found that working with sizers is the best way for me to understand what a patient wants, and for the patient to understand how a certain size will ultimatelt look. But, as with many things, this is not a precise science.
If you are uncertain about the size, go back into your doctor's office and try them on again. Take in several different tops and decide what you are comfortable with. Your look with the sizers is much more important than talking about specific bra cup sizes, as this may differ greatly depending upon where you buy your bras, and how you like them to fit.
I will usually go up 50cc from the desired sizer when I am placing the implant under the muscle. In terms of profiles, with saline implants I prefer either moderate profile implants, or moderate profile plus implants. In many women, high profile implants can give too much fullness in the top of the breast. But most importantly, I don't want the base width of the implant to exceed than the base width of your breast. This can make the breast wider than you might want.
Best advice to you, is to work with sizers again. Take in a friend, if you want, and decide what looks best with you frame size. (As you are petite, you will get a greater difference with a moderate sized implant than will someone with a larger frame.)
Good luck!
