If you want to get off the slab & enjoy what AZ has to offer (which is a TON of scenery) take 89A south out of Kanab along the Vermillion Cliffs instead of 89 east through Utah. Eventually it will end back at 89. Take 89 to Flagstaff, pick up I-40 west to I-17 south. South of Flagstaff get off on 89A again & run it through Sedona all the way to Prescott. In Prescott pick up 89 south again to Wickenburg and take 93/60 southeast to Phx. From there you can pick up I-10 & jet to Tucson. I would also highly recommend seeing the Sonora Desert Museum. You can do this long backroad trek in two long days if you keep it moving at a steady pace. Do an overnighter in Sedona or Prescott. You'll already see a ton of saguaros by the time you make Phoenix but they get much thicker down around the desert museum & Tucson area. 89A is definately one of our most scenic routes in the state.
Excellent advice from Gary Miller, a long time Arizona rider; couldn't say it any better myself, this is the routing you want. Greg, you and Paul can stay at my house while you view Southern Arizona. Honestly, it will be too damn hot to camp out in the Sonoran Desert at the end of May or the first week in June. Go out on your day trip rides, then come back to Barrio del Chandler and we will drink beer (a lot of beer!) in my swimming pool! MI Casa es su Casa ese, JSNS!