Not to be negative, and hopefully its not what it sounds like...but if you are "tired" of your ball pythons should you really be adding another snake? What happens when you have half a dozen reptiles that you are "tired" of? Most often this is where neglect sets in accompanied by poor husbandry. That said if your just looking to add something different (and can keep that spark for your balls), there are lots of other python species out there. You might look at what type of conditions you can consistently provide and how much space you can devote. Knowing these things ahead of time will ensure that whatever you choose lives a long healthy life.