They tend to be nippy as hatchlings, but tend to outgrow it quickly. My girl was no exception. She struck a lot a first, but within a handful of handling sessions she mellowed right out. She hasn't struck at all since probably the fourth time I handled her. She's curious and gentle while out now.
I don't know how carpets age, but Bredli get more of that orangey reddish color towards the head and a dark rich black towards the tail as they age.
My Bredli won't be my only species of Morelia for long. And based on what you're looking for for I think you'll be happy with a carpet or Bredli.