Question regarding Node References or Node Hierarchy

Hi,

I am putting together a site that will use a Ubercart store to sell subscriptions to online video courses.
My main question is how to layout the product pages. Each product is video course and requires a lot of information about the course.

I have broken it down into sub categories which I think the best way is to do seperate nodes for each.

Course - The main Ubercart product node.
--Section 1
----Chapter 1
------Part 1
------Part 2
----Chapter 2
------Part 1
------Part 2
----Chapter 3
------Part 1
------Part 2
--Section 2
----Chapter 1
------Part 1
------Part 2
----Chapter 2
------Part 1
------Part 2
----Chapter 3
------Part 1
------Part 2

The course node will also have information about the course as a whole and also subscription info etc.

I would also like pathauto to create paths like courses/course-1/section-1/chapter-1/part-1

I need to know which is the best way to arrange the nodes so that they will relate to each other and it is easy to add or edit the child nodes. I have looked at Node Hierarchy and also Node Reference. It looks like Node Reference is the more powerful of the two.

What I cannot work out is the way around to put the references. Does the node reference go into the parent node or int the child node. If it is in the parent then I can use an auto create to build the child nodes from the parent but then I have an issue with pathauto not building path names in a logical format. If I put the reference in the child node then pathauto sort of works but only for the first parent. I cannot get it to work for the grandparents.

Once the site is built then the maintainence will be handed over to someone else so the adding and maintaining of products needs to be easy.

Thanks.

Roger.