Ok guys, after all of your advice, we've decided to spend our trip in 2 locations : near Zion NP and near Moab. Update : We are toying with 3 locations too : Zion, Grand Canyon North Rim and Moab.
We will have 10 nights total to spend outside of travel (trip is 6/30-7/15).
If the 2 stop option: Would you suggest 5 nights in each location? We will visit Zion first, as it's further from home. If this option, we will do day trips to Bryce and GCNP while at Zion. Also, day trips to Arches NP and and Canyonlands NP while in Moab.
If 3 stops, we are thinking 2 nights in Grand Canyon, and 4 at the other two stops. Reason being that we've been to the South Rim years ago, and will visit GCNP again in a few years to do the full hike to the bottom.
If you have any "must do" things in the locations, please let me know!
For CGs, we will probably use Zion River in Zion. I know there were a few negative suggestions for that park, but for our intended plans, it makes the most sense travel wise.
I'm just starting to look into Moab and the North Rim. We tend to use KOA often due to kids ages, but I'm definitely open to suggestions for CGs there. Any suggestions are MORE than welcome!
Thanks a ton in advance!