Now the big questions, before I fully commit to this idea, how do I make this happen?

Using wood would be ideal for the stability of the piece but could also pose a danger or even a disaster of not being able to suspend it. This lead me to think about using cardboard and gluing multiple pieces together, against the grain to make it light weight and stable.

Now how to not waste multiple sheets of high quality water color paper? Create a cardboard infrastructure in the middle of the book pages to create stability and use less paper by filling around the structure, rather than laying several full sheets onto of each other.  

Now the questions remain whether I should use multiple sheets of 140lb watercolor paper, or less sheets of 300lb water color paper? Or use 140lb paper for the flat pages and 300lb for the pages falling downwards? Also, with all the pages and glue this is still going to be heavy, do I find a way to suspend the book and make it look intentional or try and make it less obvious?