Once in NM take Hwy 90 at Lordsburg up to Silver City, head east a little on US 180 and catch Hwy 152 at Central. Take 152 east to I-25. We found 152 by accident while detouring around some mud during the Divide ride in '07. Really terrific twisty paved road!
It would be a cryin' shame to go through NW Arkansas on I-40
Some of the best riding in the country to be had. I would cut NW from Little Rock up to Joplin, MO (or maybe Springfield) before heading west. Hard to go wrong in that area but I might be able to come up with a route for you.