There is no difference between males and females with aggression. That would be completely up to the individual boa. The only problem is that at a show the snakes tend to be cold and therefore all appear docile. In general though boas are very docile and inquisitive. Just pick one from a breeder that routinely handles their snakes and you should be good to go. Be prepared to provide it with a 4x2 enclosure as an adult.