First, are you talking about this September (2016)? Do you need motels, or do you plan to camp? Your itinerary may be dictated by where you're able to find openings; make reservations as soon as possible. The rest of my response ignores that issue.
I agree with Zivvi about the Grand Canyon: one rim is a good idea. If you've never been there before, I'd recommend the South Rim at Grand Canyon National Park. It's more accessible than the North Rim, has closer views of the canyon bottom, and has more of the iconic views shown in magazines. I also like the North Rim (it's much less crowded), but would save it for another time.
Of the places you mentioned, Zion is my favorite. It isn't spectacular when you first drive into it; you need to hike a bit to find its treasures. Two wonderful day hikes: (1) The Narrows, where you walk upstream in a small river, between towering sandstone cliffs; (2) Angels Landing (if you can tolerate heights) has great views of the canyon. There are many, many other hikes as well. I usually spend three days there, and have visited five times in the last decade.
Bryce is much more easily viewed. Drive along the scenic route, and stop at a few of the overlooks (sunrise and sunset are special times). There is also good hiking, but you could see a lot of the park in one long day, or two days if you have the time.
You mentioned Escalante and Grand Staircase. Grand Staircase-Escalante National Monument is very large, but mostly without paved roads. However, there's a bunch of stuff in the general area. I'll mention a couple of places.
Page didn't thrill me, but it has a few things worth seeing: Antelope Canyon; Glen Canyon Dam; Horseshoe Bend.
Capitol Reef National Park is just to the north of GSENM. It might be worth a couple of days. If you go there, take Route 12 to Bryce; it has excellent views, and there are potential stops and short hikes all along the way.