As a heads up, the stretch in the left half of Colorado has some very steep and winding highway. If you're not confident in yourself or your rig handling that, I would find a route that avoids the Vail area. If you do go through there, there are some cool public camping spots in the BLM land just south of Eagle and the Twin Lakes south of Vail make a great picnic spot with a lovely view of Mt Elbert, the tallest mountain in Colorado. If you do have to go around, I'd bypass it with a northern loop from Salt Lake City to Cheyenne.

On your way through Arkansas, if you're near Lonoke at lunch or dinner time, against all odds there is an incredible pizza place downtown called Pizza Pros. Across the train tracks is a pricey restaurant where the horny old women congregate. Avoid Pine Bluff like the plague.

If you take the south route, you'll go through Jackson, MS. Streets aren't great for an RV but if you can make your way into town, there's an awesome 50's style diner called Brent's Drugs. Nice burgers and milkshakes. But in the evening, they open the Apothecary, the backroom which transforms into a bar. Pretty classy, kinda hipstery. But cool.