I have read that there are studies about it and that people have quit drinking/drugging and smoking at the same time and have successful, but can't recall where I saw this at. So hopefully someone will be along with the right links.
But, me personally, I'm taking it one addiction at a time. I'm waiting until I'm more comfortable with sobriety away from my drinking before I try to give up smoking. Drinking was my big problem, so gave that up first and plan to give up smoking when I'm more comfortable and more than a couple months away from booze.
Guess it depends on the individual though. I'm sure you'll know when the time is right for you to give it up. Take it a day at a time and when the time comes it'll be easier and you'll be ready for it.
Wes