I sure wish that I could make this one! About a decade ago, I set up a very similar trip from some friends from around the country. When at the Koontenai Falls area and the swaying bridge, take a walk down to the river. You should see some PreCambrian ripple marks in the rock under your feet. They are close to a billion years old!
If you get close to the small community of Yaak and are looking for a fun place to camp overnight, check out Hensley Hill. I think it was the site of a military radar site or something like that. A narrow winding road takes you to the top. The night views are incredible if you are into star gazing. Check with the USFS if it is still accessible.
The road from the Ten Lakes area to the west side of Glacier is one of my favorites!
Wishing you all the very best time! This is going to be an incredible journey for all of you. Bring bear spray, ha ha!
Dale, the old fart