615cc/585cc SRX implants. Will it look proportionate to my body? (Photo)

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.
 Ultimately, careful communication of your goals (in my practice I prefer the use of goal pictures, direct examination/communication in front of a full-length mirror, in bra sizers, and computer imaging) as well as careful measurements (dimensional planning) will be critical.
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 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. For example, I have found that the use of words such as “natural or fake look” or "D o DD cup” or "proportionate" 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, the use of computer imaging has been very helpful during the communication process, in our practice.
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, after the use of temporary intraoperative sizers.
I hope this helps. Best wishes for an outcome that you will be very pleased with. 

Hello and thank you for your question.  The
best advice you can receive is from an in-person consultation.  The size, profile, and shape of the
implant is based on your desired breast size/shape, your chest wall
measurements, and soft tissue quality.  This decision should
be based on a detailed discussion with equal input from both you
and your surgeon.   Make sure you specifically look
at before and after pictures of real patients who have had this surgery
performed by your surgeon and evaluate their results.  
Best wishes and good luck.
Richard G. Reish, M.D.  FACS
Harvard-trained plastic surgeon

Thanks for your question. Without seeing preop pictures and doing a formal evaluation, it is hard to comment on your particular case. In short, these sizes will not be "proportionate" b/c they are simply very large. The photo you've posted however is arguably not proportionate either, and so it might be a matter of saying that you just like this "look" better. The number one predictor of implant malposition, asymmetry and the need for revision is large volume of the implant. Statistically, implants over 350cc have higher risk of the above. That however must be tempered to the individual. It is crucial to use dimensions when planning so that the implant will "fit", but it is also equally important to asses the quality of the breast tissue, skin, etc.The implants that have been chosen exceed each of your base diameters.  A larger implant is heavier and the more weight present, the higher likelihood of implant malposition. This is particularly true in the long run. I personally would not use this large a size b/c  I believe the risks are too high. If you are having second thoughts, I would recommend visiting with your surgeon again.Best of Luck!