If you are hikers then you could spend 2 weeks in Bryce, if you just want to drive the road and get out at the scenic overlooks then less is enough. But two days would give you time for a couple of good hikes, maybe Queens Garden and the Navajo trails.
On any hikes remember that you are flatlanders and even moderate climbs will be a lot tougher than you expect. The altitude will get you and you aren't spending enough time to out there to adjust to it. Also carry twice as much water as you think you need.
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Kartchner Caverns - http://azstateparks.com/Parks/KACA/ 1 night
You can go to Tombstone and pick up Bisbee and Tombstone -
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Those are in southern AZ they want to go north, LOL. Talk about adding driving time.