Bear in mind it's not just the size of the snake but it's attitude.
I have Savu pythons which are the fourth smallest snake in the world, but they are lightning quick and constantly on the go. They're docile enough and easily handled, but not a snake that will just lay on you and chill like a BP will.
I also have a garter that is smaller, rescued her from the garage where we found her injured a few years back, and about every other day I want to toss her back outside because she is just not adapting to captivity.