Volume estimate to achieve my ultimate goal? (Photo)

It is generally unwise to pursue excessive volume. The tissue support will eventually fail and be irreparably stretched/thinned. To say nothing of the musculoskeletal issues that stem from the added weight.

That being said...if you are pursuing excessive volume despite the risks, you will likely need to consider staging procedures with each subsequent exchange an opportunity to upsize.

The best advice is to find a size that fits your frame.

As always, discuss your concerns with a board certified plastic surgeon (ABPS).

In order to achieve the size in your wish photo you will likely have to have staged procedures. Start by visiting with a board certified plastic surgeon near you for a consultation. During this meeting your surgeon will measure your breasts (This is different than bra sizing) and will inform you of implant size options. Be sure to review the risks that are associated with implants this size so that you can make an informed decision.

No, you really do not want that size because it will stretch and thin your own tissue, sag with time, and be much too large and heavy for your neck and shoulders. Plus, it will be hard to wear dresses. It would be much better to find a size that works with your frame and tissue, that looks good, and that you can enjoy for many years.