I told my doc right at the beginning that I didn't want a goal weight and he never brought the subject up. But I do know from those on the same bariatric course that the goal weight they were given was on the generous side of the normal range using the BMI charts.
Healthy Weight Calculator for a Healthy Weight Range – www.HealthAtoZ.com
And I never decided on an actual weight. My goal was just to get into the "normal" BMI range for my height of 5'5" and that went from approx. 111-150lb .
Once I got there, ultimately, my body settled on 118-120lb which is on the lower side of a normal BMI but good for my small frame.
My advice is not to put pressure on yourself by chosing an end weight now. Make your goal just to be slimmer and healthier.