We did a similar trip last year:

Hilton Scottsdale (Scottsdale is near Phoenix and a really nice place to visit)
Hampton Inn Scottsdale
Hampton Inn Prescott (Prescott is OK, but next time I'd stay in Sedona)

then HGVC Las Vegas Strip (Viva Las Vegas )

on the way back:
Garden Inn Flagstaff (Boring!)
Hilton Sedona (Hi-light of the road trip, will definately return)
Homewood Suites Scotsdale
Hilton Phoenix Airport

then we flew to Vancouver, but that's another story

Didn't go near the Grand Canyon, except across the Hoover Dam, as we'd been there before. Although when in Las Vegas we drove out to red-rock canyon, which is nice but not a patch on Sedona.

Sedona is the best place for scenery, etc. The Hilton is a little way out of town, but as you're driving that's not a problem. Close though to a discount shopping mall and some local restaurants.
I'd definately try and stop in Scottsdale as well.