Hi Jeff,

I just came off a Utah roadtrip with my sons and I could recommend all of the parks you mentioned and add Capitol Reef National Park. Dinosaur NM is closer to SLC (I think) but honestly I think that any of the other spots you mentioned are far better choices.

Sean D also makes a good point about being able to hit Bryce and Zion within a day. You could also hit Arches and a portion of Canyonlands in one day as well. I say a portion because there's three different sections to Canyonlands, one of which is within 45 miles of Arches. Plus, Moab is a cool little town to visit.

Keep us posted as to your decision.
~Brian