Hi, In 09 I was in Moore and came back through the Panhandle, I didn't have the time so I bypassed the highest point in OK, Black Mesa, nice campground also. Then take NM456 to Capulin Volcano NP and drive to the top. I went up into Colorado from there, since you are headed to Zion 1st you'll probably want to head more southerly. I always wanted to hit Pie Town NM.
Then there is Petrified Forest, Meteor Crater, Grand Canyon, stop in Hurricane UT and see Matt's Offroad Recovery........
just some ideas.