Depends on how much bigger you want to get. Remember though bigger snake, bigger responsibilities, (and poo ). There are many different locality of boa which range in size. I am working on getting a Hog Island which generally range between 4-6ft. Whatever you choose make sure you do your research and if you pick one of the bigger ones be positive you will be able to care for it when it does reach full size. Many people dump their pets because when they get so large it's a lot of work. Good luck with whatever you choose.