I went the northern route out, Nashville, St Louis, Kansas City, Denver, through the Rockies. If your towing do not go this route. I chose to mainly for the sake of seeing the Rockies and driving thru them. It's very stressful and would never consider it in a tow rig without an exhaust brake. I70 is te tallest interstate in the country at 11k+ft with about 16-17 miles of 7% down Eisenhower pass and Vail pass. It's also good for around 2mpg worse on fuel mileage.
I came home across 40, which I had seen before but was alot more tower friendly.
In a moderate rig you can't see all of Moab in a week. The trails seem to go forever, I picked up a book called back country guide to Moab. Get one its worth the $30. I camped at Canyon Lands camp ground which is a very nice place/ clean. It's downtown so you can walk around town at night or to dinner.
Sucks thinking back today last week I was wheeling out there. Do as much as possible, time flies and its an awsome place.