Columbia Breast Implants doctors

I have to agree with Dr Hochstein on two counts.  
1) It doesn't appear to me that you have a tuberous breast.  You definitely have drooping and at most a very mild component of constriction if any at all. 
2) I never place implants on top of the muscle any more.  I haven't performed Sub Glandular Augmentation in about 10 years.  There are so many benefits to Sub Muscular that it's hard to justify doing subglandular implants at all.  Capsular contractures (tightening of the capsular tissue making the implants feel hard), cancer detection on mammograms, little to no chance of synmastia (implants too close together) and much less chance of bottoming out, etc..... are all better under the muscle!   So, even if there were a slightly better cosmetic outcome with the implants on top of the muscle, I would still recommend under the muscle for the long term outcome.

There is barely a noticeable difference between 300 and 325 cc. You should try on implants and see if you can appreciate a difference - make sure whoever is doing the sizing does not tell you which is which. 325 cc should not put you over the edge. Generally the belief is that women get modest during sizing, then wish they went with a little larger implant.  Either way I think you should have a nice result.

You are petite in your height and weight, and it's impossible to answer this question without photos to show your chest width, degree of deflation in the breasts - many factors. The most important factor is chest width, and your surgeon needs to match the implant choice to your chest width. If the implant is too wide it will not look right. Having said that, a difference of 25 cc is about a shot glass in volume and may not represent a visible difference. Good luck!