If you want a larger snake, I would go with a female. They will push 9-ish feet in length. Some males will stay relatively small - around 6 ft. If that's big enough then you'll be happy with a male, but if you really want size, I'd go with a girl...
Temperaments really are about the same for either sex if that's something you were worried about...
Incidentally, consider cage size for a large snake. An adult female BCI should have, in my honest opinion, a minimum of a 6x2 ft cage. An adult male would be fine in a 4x2. Some may say they can get along in a smaller enclosure, but they really do need the space to stretch out. I think these measurments are fair. Just something to consider....![]()