Distant, severely pendulous breasts on a large ribcage-- what procedure could help?

A breast lift will restore shape and symmetry so that should definitely be your first step. Once you are at your target weight, you will be in a better position to select implants of the size you want.

First, congrats on the weight loss. I would have you at your goal weight for 6 months prior to any surgery. This allows for everything to settle out and give a better long term result. At that point, I would do a 2 stage surgery. First, I would do a breast lift (mastopexy). I would allow this to heal for 6 months to 1 year. Then, in the second stage, I would place an implant. I know that's a long time to get to the final result but wouldn't want to risk something unsatisfactory just to speed things along. I would not do the implant at the same time as the lift as it may cause wound healing issues and possible nipple death!

As always, be sure to research who performs your surgery to ensure the best likelihood of a positive result

A lift can reshape your breasts to make them less pendulous and perkier. Augmentation with implants can also help increase size and further improve roundness. It would be best to define what “normal and youthful” is, so you can better describe your goals to your surgeon. That way, your surgeon can then determine which treatment(s) would be most suitable.