You should also be aware of a few things regarding the Brazilian Butt Lift:
a) It can be expensive, approaching the cost of SRS/GCS.
b) It's not guaranteed. If the transplanted fat does not connect to a new blood supply, it will be absorbed elsewhere.
c) If you're already very lean, you may not have sufficient abdominal fat to extract and transplant.
d) If there's already very, very little fat on your buttocks/hips, transplanting more there will likely not be successful.
e) there's a very long healing time (several weeks) during which you cannot sit down
For the expense, padded panties are a much, much better option. Unless your goal is to look great in a bikini at the beach, this just isn't a great procedure, for the large amounts of money and time required.