A Red Tail Boa would be a great next step from Ball Pythons. That's what I did! I had a Ball but my boyfriend and I wanted to get into the larger snakes, and BCI's are a great way to get the experience. They only get around 6ft or so for males, 7ft or so for females, the largest common length being MAYBE 8ft or 9ft. BCC's are bigger than BCI's but still nowhere near as big as Burms or Retics, definitely. And they have just lovely attitudes and temperaments.