Setup Numerous Facets

We are setting up our SC store which will have around 100,000 items.  Each of the items can have a variable number of attributes and the attributes change based on the type of item.  For example, each item might have some fairly generic attributes like category, color, length, and width, but they all also have very specific attributes within categories, like scent, number of pages, material, etc.  There are a host of these specific type attributes depending on the category.

What's the best approach to handle this?  I have read NetSuite only recommends around 40 facets, but we will have thousands if we make each attribute a facet.  I also don't relish the idea of have a thousand custom fields available on each item record.  Lastly, even if we setup all of these facets, I do not see an easy way to build a facet hierarchy such that some of the broad facets, like Product Category, must be selected before showing the facets applicable to that category.