The Brazilian Rainbow Boa is personally my favourite snake in my collection. She's awesome. She was my first snake ever and I've had her since she was a baby - still to this day she has never bit me.
Some of them can be snappy as babies - but a lot of them are actually super chill! Really awesome snakes, because they are in my opinion one of the most beautiful non-venomous snakes you can get and their personalities are just awesome! They get big - but not too big. I can also almost guarentee that they will ALWAYS eat! Their monsters when they see food, so no issues on eating either.
I would definitely recommend you get a BRB. It was my first snake and she got me into an on going reptile addiction haha