The amount of weight that you lose, your age and genes, and how you carry the weight in the first place are the major drivers of whether or not you are going to have excess skin. You can lose weight super slow, and still have tons of extra skin. You can lose it quickly, and have virtually no excess skin. I wouldn't let that be the determinant of which surgery I have.
You should speak to your doctor about his/her preference based upon your bmi, health history, whether you already have gerd or acid reflux, etc.
Congratulations, and good luck on your journey!