Am I a candidate for an plus size extended tummy tuck and bbl? (photo)

I perform the lipo/TT and BBL in combination for many of my patients.  However, if they prefer staging the procedures I always recommend the lipo and BBL first, followed by the TT three to six months later so that the result will be as tight as possible. 
A TT addresses both the loose skin and the lax abdominal wall as to give a nice, flat youthful contour to the abdomen.  The TT also creates a more youthful belly button.  TT without muscle repair may make the recovery easier, but, if you have laxity in that area, the result will be better with plication. In general, the muscles should be brought to anatomic norms. The smaller the separation, the less tightening required and probably the less discomfort. Swelling will occur irrespective of muscle repair, and almost every patient requiring a TT will benefit from the muscle repair.
I place the scar as low as possible. This will be below the level of a C-section scar and almost to the level of the leg crease. With the low scar, the scar can be concealed by virtually any piece of clothing.  The key is how the tension is managed at the end of the TT. Schedule an appointment with a board certified plastic surgeon.

With weight loss a circumferential abdominoplasty would both remove excess tissue and lift and shape your butt.  Fat could be added back into the butt for increased volume and projection.