Is 325cc or 300cc better for me? I'm petite, 4'11", 95lbs and looking for natural but full breasts (Photo)

You should try some implants sizers in a bra.  that would be one great way to assess the volume you need for your augmentation. 

It is not likely that the difference between 300 and 325 will cause a problem.  If you are trying to decide, I would suggest 325 might be better.The best way
to determine the size that fits your personal perception of the perfect breast
is to try on sizers. This way you can see how they fit on you, how they add to
your current volume, and whether they fit your frame. Although the surgeon can
guide you, only you will be able to tell what is the right size. Try on sizers.
Measuring a diameter and then telling the patient what volume they can
have (in high, moderate or moderate plus implants) in my mind is backwards. The
patients should be allowed to choose the volume. Then the surgeon carefully
considers the base diameter, projection, profile, manufacturer, and fill
material that will achieve the patients goals of size as well as qualitative
look (natural, intermediate, or bold upper pole fullness or projection), all
the while taking into consideration the patient's anatomic features that will
affect the outcome. The experience of the surgeon and the degree to which
they explain the options to you is of utmost importance. The subtlety in the
final outcome is not achieved by which profile implant is used, it is
determined by the skill in the creation of the pocket, the choice of implant.
Don't let the doctor tell you what would look good on you. They cannot tell
what you perceive to be the best size. That is up to you.