Transgender patient 500cc moderate or 550cc moderate plus? (Photos)

So I'm having a really hard time deciding on the size I'd like to go with. My surgeon says he's comfortable doing whatever size I choose, I'm just very indecisive. I want a nice natural look to my breasts. I just need professional opinions on which would look best for my frame. I'm a trans female and have been on hormone therapy since I was 15, I'm 19 now. Should I go with 500cc moderate or 550cc mod plus? I should also add I'm going with saline under the muscle. My goal would be a natural D cup