The cage size is fine but I would ditch the "nest box" section for actual hides. BP's like small confined spaces where they can feel secure. A 1 size fits all isn't going to work.
I would suggest these made by reptile basics. Replace with the correct size as needed:
http://www.reptilebasics.com/hide-boxes
This is what my cages look like:
And here is a thread about them:
http://ball-pythons.net/forums/showt...With-Pictures!