Actually it does not matter whether you chose a little boy or girl, both will remain very kind and playful in case they are spayed / neutered in right time.
Our kittens are spayed / neutered early in their childhood which provides faster and easier recovery. They will behave as young kitten since their whole lives. They will be more playful and more lovely.
The most people think that tom-cats are rong-headed and less nice than queens. This might be true for other breed, but not for ragdolls. Some people says that spayed ragdoll tom-cats are even nicer than females.