Is 700cc saline moderate plus over filled to 750cc too big? (Photos)

It is very difficult to determine the best size you will need (recommended based on your photos) or the exact size and shape implant you will require to best match your ideal breast image without an examination by a board certified plastic surgeon. Not just any board certified plastic surgeon, but one with many years of frequently performing breast augmentation surgery including different approaches, techniques and implant choices. This is because several measurements not to mention your breast characteristics are needed to determine the optimal implant size to obtain your goals. Without knowing these dimensions it would be difficult to make this determination. For example, the existing base width of your breast will determine, in many cases, the maximal volume per implant profile that you can accommodate. To illustrate; a 100 cc difference may make a significant difference with a narrow base width breast, but much less of a difference if you have a wide chest wall and wide breast “foot print”. Therefore, just because your friend may have a great result with let’s say a 300 cc implant to make her go from a “A” cup to a “C” cup size does not mean that you will have the same result with the same size implant. The same process goes for just filling in the upper part of your breast without becoming much larger. Further simply placing implants in a bra to determine the size best for you is not always accurate as the bra often distorts the size, is dependent on the pressure the bra places plus the implant is outside your breast and not under it among other variables. Computer software morphing programs that automatically determine the best implant size can be helpful in some but not all cases (e.g. doesn’t work well in my experience with existing implants, sagging or asymmetric breasts). Using “want to be” photos however are useful if simply provided to the surgeon as I will further explain in the link below including silicone vs saline implant

I think it's too large.  You may like them initially but in time you will likely regret it as they become more uncomfortable.