Is it a good idea to get a gastric sleeve then lipo/BBL for current weight of 250 lbs at 5'4"?

Hi, Yes. If you are committed and ready to make the lifestyle and behavior modifications necessary for a sleeve gastrectomy to be safe and effective, you definitely meet criteria to have a laparoscopic sleeve gastrectomy. As your bmi is 42.9, you do qualify for a sleeve gastrectomy under the guidelines. Once you have lost the extra weight and have reached your goals, then you can undergo  lipo/BBL if you desire. You will likely have much better results this way, as well as be healthier in the long term. I recommend meeting with an experienced bariatric surgeon who can help you decide if this is the right procedure for you and to help support you to keep the weight off long term. Wishing you all the best.

Hello.
Thanks for your time and question
It is a very good idea to get a gastric sleeve and then lipo/bbl . 
Before doing a plastic surgery it is good to be close to your ideal weight, this is why plastic surgeons recommend losing weight before going to surgery. losing weight will help you to have better results and decreased the risk of complications.After bariatric surgery the best for you is wait until you reach the goal, at least 1 year after the weight loss surgery and/or 3 months in the same weight 
I would recommend you to visit a certified bariatric surgeon and discuss the best option for you.
Good luck in this journey, blessings !
Dr. Pablo