I can’t decide! 485 or 520cc and high or moderate or mod plus? (Photos)

The best cosmetic result in any particular breast
augmentation patient depends on a variety of factors, including: Your
individual anatomy, desired outcome, realistic expectations, a thorough
discussion with the plastic surgeon about the options, and an understanding of
the pros and cons of any particular implant choice. Proper sizing is not just
about the number of cc’s. or the type of implant. The thickness of your tissue,
breast dimensions which include the width, height, and projection, as well as
chest wall width all need to be considered when choosing an implant. Trying on
implant “sizers” of various shapes and volumes while wearing a tight t-shirt,
bra, or bathing suit at a preoperative visit will help you and your surgeon
choose the optimal implant.

Keep in mind that following the advice from a surgeon on
this or any other website who proposes to tell you what to do without examining
you, physically feeling the tissue, assessing your desired outcome, taking a
full medical history, and discussing the pros and cons of each operative
procedure would not be in your best interest. I would suggest that  your plastic surgeon be certified by the American Board of Plastic Surgery and ideally
a member of the American Society for Aesthetic Plastic Surgery (ASAPS) that you
trust and are comfortable with. You should discuss your concerns with that
surgeon in person.

Robert Singer, MD FACS

La Jolla, California
 

Thank you for the question and pictures.  Based on your photographs, I think that you are starting at a good place and should have a very nice outcome with breast augmentation surgery.   My best advice: more communication.
It is definitely worth spending more time (prior to the date of surgery) with your plastic surgeon to discuss further.  As you know, it will be important for many reasons, that you feel comfortable that you and your plastic surgeon are on the "same page" prior to proceeding.
One question that might be helpful for you to consider: would you be more disappointed if you are slightly too big or slightly too small after the breast augmentation procedure? 
  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. Sometimes, it is necessary to seek several consultations before you feel comfortable about your choice.
2. Have a full discussion and communication regarding your desired goals with your plastic surgeon. This communication will be critical in determining 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 "D or DD cup” etc may mean different things to different people and therefore prove unhelpful.
Also, as you know, cup size varies depending on him who makes the bra; therefore, discussing desired cup size may also be inaccurate. Again, best not to discuss your goals and/or judge the outcome of the procedure performed based on achieving a specific cup size. The use of computer imaging may be very helpful during the communication process. The use of in bra sizers may also be helpful. In other words, use as many “visual aids” as possible during the communication process. I encourage patients to meet with me as my times as necessary, to feel comfortable that we are both on the “same page”.
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. I generally select appropriate breast implant size/profile after the use of temporary intraoperative sizers and viewing the patient's chest in the upright and supine positions.
 I hope this helps. Best wishes for an outcome that you will be very pleased with.