Here's an idea, have your wife fly into Las Vegas, or Flagstaff area. From Flagstaff you can take in the Grand Canyon. It's a drive from Flagstaff, or find something closer. Then drive up to Kanab, UT. From here you can take in Zion, and the North Rim of the Grand Canyon. Then to take in Bryce Canyon I'd go to Bryce, UT and stay at Ruby's Inn & RV Park, it's right outside the main gate. For Capital Reef you drive over to Torrey, UT it's just north of the park. Or do a day trip, it's a beautiful drive too.
But in the months of June & July, your going to need reservations just about everywhere. And it's going to be a little on the warm side. So your going to need the A/C unit.