Thank you for your questions and sharing your pictures. The fat in a patient after a bariatric surgery doesn't have good properties for having a BBL. I recommend you to have a body lift and in your buttock placing silicon gel implants and instead of fat. You have to decide your priorities for working on your body because everything is not possible into a single time. First submit yourself into a full evaluation of your body (clearance) and with your surgeon decide based on the levels of your results and expectations, your surgery. Best of Luck!
The more liposuction areas that are treated, the more fat can be transferred to your buttocks
You actually have an excellent supply of fat in your tummy. The best option for you would be to combine a tummy tuck with liposuction and buttock fat injection. The tummy fat that would ordinarily be discarded at the time of a tummy tuck can be put to good use. Some people believe you cannot have a tummy tuck and buttock fat injection simultaneously because you have to lie down. However, this is a popular combination in my practice and patient satisfaction is very high. Yes, a breast reduction could be done as well, usually at a separate time (along with arm lifts). You could get all the work done, including anesthesia and the surgery center fees, for about 25K in my area (Midwest U.S.). It might be best to look around a little. A link to my website is attached with examples of these procedures. You are wise not to have buttock implants.
Body contouring after weight loss
Congratulations on your weight loss! Know that there are techniques that have been described that take advantage of loose skin in body contouring. While you may not have sufficient adipose tissue for a traditional BBL, the soft tissue and skin that may be discarded during a body lift can be shaped, mobilized, and positioned to achieve gluteal augmentation as an autologous buttock lift. Similarly soft tissue of the lateral chest wall can be employed in shaping the breast, if you are averse to implants. Consider seeing a Board Certified Plastic Surgeon with a concentration on post bariatric body contouring. Best of luck!
BBL an weight loss
You might consider a BBL at least to try to fill the buttocks with whatever fat is available , then undergo a lower body lift, and all the other procedures you want. I have treated many bariatric patients over the years. Good luck.
Alternatives to BBL?
First, congratulations on your weight loss. Second, in cases like yours where the body has kind of been deflated, the only way to plump back up the breasts and buttock permanently is with implants. All types of lifts and tucks in these two areas will significantly further flatten them, hence the need for volume restoration with implants. Glad to help.