I'm sure you're overwhelmed by now. However, I would like to add a few more comments.
- definitely check out one of the above poster's link 'Southwest Trip 2014' by Tragusa3. He began planning about a year prior for his big trip with the family. This forum gave him a lot of help and consequently, he did make changes to his original plan. Many of us have been to the planned sites and could give additional help and time needed.
- You have a Jeep. Moab is one of two of the best places for Jeeping. (The other would be Silverton, Colorado just north of Durango). The trails are awesome and unlike anywhere else. Your family would absolutely love getting out on those trails of slickrock. The scenery is beautiful.
- You planned to stay at Canyonlands - great place. Don't forget to tour Arches Nat'l Park nearby. Something the whole family would love is the ranger-led hike called 'Fiery Furnace'. Check it out on the park's website. You need reservations for it. Arches could take a couple day's time in itself.
- all of the national parks have excellent web sites with very helpful information such as 'Things to Do' and road updates. Also, hiking information and campgrounds. Check them out.
- if you get to the Grand Canyon, definitely hike down the Bright Angel Trail if only for 1/4 mile or so. It will give you an altogether different perspective of the massive canyon rather than just standing on top. Remember...going up is a LOT more difficult. Take lots of water.
I really hope you can shortened the miles for your trip. You'll enjoy it much more.