First, wander over to this thread:
https://texags.com/forums/54/topics/2852777**********
It covers some of the same far western areas. It also has a link to a photo thread of mine that covered Yellowstone, Tetons, Dinosaur, Grand Canyon of the Gunnison and a few others.
Next, a recent thread, in which I link a lot of threads concerning Palo Duro Canyon.
https://texags.com/forums/39/topics/2846493*****
And if you just want to hit New Mexico, here's an old thread about must see places in New Mexico.
https://texags.com/forums/34/topics/2436800***********
My first thought on the trip in general, is you're in for quite a beatdown. If you did nothing but drive to the Grand Canyon and back, you're spending about three hours a day doing nothing but driving. About 40 hours total @60mph.
You have two weeks off and you're considering spending one full work week in the car? Not my cup of tea.
I'm also not keen on a southern route in the summer. I love Big Bend, Ft. Davis, Carlsbad, White Sands, etc. But in the summer, the temperatures are ungodly.
And if you're thinking about Grand Canyon, Utah, and Western Colorado, I'd suggest you hop on Southwest Airlines to Albuquerque, then rent a car.
All of your destinations sound good, and you're getting some good input. I'd just take a good hard look at the driving distances involved and your tolerance for the same. While some of the western deserts are fascinating to travel through, some are just flat out boring.