I've been using one of the green "leader book" holders from Rite in the Rain for a little while now; item number C9200A. It's not perfect, and I haven't figured out a way to keep the Note 8 really secured in the binder itself, but there are several pen slots which are big enough to hold a highligher/sharpie/etc, and a few other slots and pockets for smart cards or anything else. And the dimensions are perfect for holding the tablet.
The ones we get from supply (I'm Army btw), come with a packet of inserts that has graphed notebook paper, and fillable pages for things like a 9-line MEDEVAC request, call for fire request, unexploded ordinance, and others. Some of it might be Army specific, but I'm sure you could find it useful too
Anyway, I've been in the same boat as you for awhile, and besides finding some "tactical" (lol) iPad Mini cases/binders, I haven't been able to find much. Let me know if you find something better!