I am having problems with picking an implant size. Should I go with 395cc or 355cc? My goal is to be a full C cup.

Thank you for the question and pictures.  You are starting at a good place and should have a very nice outcome with breast augmentation surgery. As you consider breast augmentation surgery, the most important decision you make is NOT size/profile of breast implant, but selection of plastic surgeon. Generally speaking, the best online advice I can give to ladies who are considering  breast augmentation surgery ( regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully.  Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.  2. Have a full discussion and communication regarding your desired goals with your plastic surgeon. This communication will be critical in determining which operation and/or breast implant size/type/profile will most likely help achieve your goals.
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as “natural” or "full C, small D cup" etc means different things to different people and therefore prove unhelpful.
 Also, as you know, cup size varies depending on who makes the bra; therefore, discussing desired cup  size may also be inaccurate.   Therefore, I ask that my patients not base their communication preoperatively OR  their satisfaction with the outcome of surgery postoperatively, on achieving a specific cup size. The use of computer imaging may be very helpful during this communication phase.
3.  Once you feel you have communicated your goals clearly,  allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals.  Again, in my practice, this decision is usually made during surgery.  The use of temporary intraoperative sizers, viewing the patient's breasts in the upright and supine position, are very helpful during the breast implant selection process. Remember, especially given your petite frame, that there may be limits as to how large of a breast implant can be utilized “safely” during your procedure.
I hope this, and the attached link (dedicated to breast augmentation for petite patients), helps.  Best wishes.

Basing the success of breast augmentation on cup size is not advisable as cup size varies considerably from company to company. Implant selection should be a collaboration between the patient based on her needs/objectives and the surgeon based on his or her expertise and experience. There is not a significant different between 355 cc or 395 cc. Ensure that your surgeon understands your goals/objectives before you proceed with surgery.