I played around with different models. We basically need to instantiate after the class is defined for the child resource chaining (since {list,item}_child_resources[] references instances of other classes). That's too late for the resources class. We can't instantiate here.
The model I'm going with is to have a class per resource. The file imports the instances from the other resource files that it needs for the child chaining. Each one does that. In the end, the init.py will load the Resources class instance and have it set all the members to the resources that are needed. That way, we break the circular references caused by handlers calling get_object on other resources. We still have the resource files importing dependencies, but only to build the tree.