How to go about setting up complicated category structure?

Hello all,
I have a site of resources which I need to build a category structure for, and am confused about the best way to go forward.

The resources will be limited by age group: kids, teens, young adults, adults

And also by resource subject: divorce, bullying, drug abuse, etc.

And then, finally, by type: video, photograph, story, etc.

I was thinking about doing custom post types to keep the resources seperate from the rest of the content.

I need the navigation to be by age group, with drop downs underneath for each subject type relevant for each age group. ie:

teens
|_ divorce
|_ bullying
|_ drug abuse

kids
|_ divorce
|_ bullying

And, finally, I’d like some sort of selector widget on the sidebar along the lines of:

I am a [age group select], dealing with [subject]. (optional) show only [resource type].

Should I use categories for all of these? Tags? A mix of both?

Thanks!