Hi Sappho
Everybody is different, some people are lucky and are left with minimal amounts of skin, it depends on your age, the amount of weight your losing etc.
In my case I previously lost 19st and had 2 stone of excess skin. I did have an upper arm lift to get rid of the bingo wings, I still regret having that op today ! the pain was unbearable and I've been left with disfigured arms and still some pain and numbness. I was going to have the lot done, breast reconstruction, full body lift and upper thigh lift, but pulled out of the surgery to have a baby.
I have my baby now and have piled the weight back on. My bypass op is on the 15th November 09, and I have no intention to undergo any op's to have any skin removed. I'm going to be happy living with it this time round.
I'll just invest in some good hold in knickers, no one can see your excess skin under clothes, and remeber excess skin is not a danger to your health, unlike the excess weight.
Your still young and 9 stone ain't an excessive amount to lose, you should be fine. Drink plenty of water, I've read that helps.
All the best
x