You driving in an rv or just the car/truck? Amarillo has the big texan steak house but they also had a pretty decent chinese restaurant forget the mile exit but the kids liked it. Also in Gallup there is a PONDEROSA steak house mile marker 16 I think we make effort to stop each time through.
As to stops the painted desert and petrified forest are basically the same and can be done in about 1/2 day if just looking. Stay at the KOA unless mil retired in flagstaff. If mil retired go to Ft Tuthill and day trip out of there.
Stop at Montezuma castle on way to tucson, can also go down the highway from there to camp verde, pine, strawberry, payson if taking time.
Now when we travel just by car/truck the trip is a stop in amarillo from tucson and then someplace just north of St Louis as they are about a full day drive apart but we travel around 89 mph when traveling without trailer or rv. Route on Hwy 54 in NM to 40 out of tucson is scenic yet quiet. End up in santa rosa/tucumcari area on 40. Get to go thru white sands range on north side of el paso.