When am I big enough to be accepted for a gastric band?

Depends. Insurance companies generally want you to have a bmi of 35 with an illness or 40 without. Check w a weight loss surgeon.
Programs vary. Usually bmi of at least 40. Between 35 and forty with comorbidities such as sleep apnea, severe hypertension, diabetes. Medically obese for over 2 yrs and failed traditional wt loss therapy.