Lisa,
The Expedition Journal pages will definitely be needed for the plans. There are some primary source documents in them, many maps that the students need to refer to, shade, label, etc., and places to write written narrations, take notes, outline, etc. The guide actually won't function without the Expedition Journal.
The World Religion & Culture's Notebook is also very necessary. It is filled with graphic organizers specifically designed for the assignments in the World Religion & Culture's study. We pondered long and hard about whether specific notebook pages would be needed in high school, (because they are so time consuming and costly for us to make as they need a graphic designer to design lay out each page).

But, we have found that the pages are a necessary tool, because I need them in order to customize our plans to truly match what the kiddos are reading and studying each day. There is truly no way to write the guides the way I desire without them!
We actually have found that principals and supervising teachers are very impressed by both the look and the content of the notebooks and that this help validate the student's work by providing an organized, visually appealing portfolio as one means of assessment.

This saves you time in having to create a portfolio later and provides a chronological record of your student's work that can be shown at any moment as needed.
Blessings,
Carrie