Terrified of choosing a breast implant that is too large! Will 300cc, 325cc or 350cc's bring me to my goal cup size? (photo)

You have a very tiny ribcage, so you need to be careful to not choose an implant that is too wide.  You may want to discuss with your plastic surgeon the option of a high profile implant.  The measurements that are taken are very important to review.  At our office we use the guide of 200 cc per cup size, so a 300 cc implant size should put you a cup size and a half larger.  You should try on the implants in the doctors office to make sure you are comfortable with the size that you choose.  Best wishes to you!

At
size 32 each 100 cc’s of implant corresponds to 1 cup size change. 200 cc implants would take you up to a size
C. I always recommend small round
textured silicone gel implants placed retro-pectoral since they look and feel
more natural, are more stable, less likely to ripple or have complications
needing revision. Implant profile is
irrelevant in the retro-pectoral position since the muscle compresses it. I recommend a new technique called Breast
Augmentation with Mini Ultimate Breast LiftTM. Using only a circumareola incision it is
possible to reshape your breast tissue creating upper pole fullness, elevate
them higher on the chest wall and more medial to increase your cleavage.
Through the same incision, implants can be placed. Aligning the areola, breast tissue and
implant over the bony prominence of the chest wall maximizes anterior
projection with a minimal size implant. Best Wishes,Gary Horndeski, M.D.

Your question is best answered by "trying on" implant sizers in the presence of your surgeon and deciding what volume in cc's matches your desires.  Just going on cup size alone can be misleading.You do not have  a lot of excess skin so there will be some limits as to how large an implant you can have. 

I think that trying on sizers in the office is the best way to get a sense of the size.  I think that the sizes you have listed are all reasonable. Find a plastic surgeon who performs hundreds of these surgeries each
year, has great reviews, and has great before and after pictures.Kenneth Hughes, MDLos Angeles, CA

You need to have your surgeon measure your base width, your nipple to fold and assess the degree of stretch you have to come up with a value, without seeing you I would expect to offer something like 255-275 though