I love my Garmin Legend, have Garmin Topo Cd's too, the Legend's 8meg will hold 1/4 of Texas from the CD. Neat to watch it plot your progress live on the screen map. That being said, I have a typical road atlas in my truck, but its only for La. its called "The Roads of Louisiana". Maybe one for Texas in bookstores? Mine was $16.95. Not quite full topo detail, but its close. Its like carrying a whole set, all nicely bound together. I refer to it all the time. Easy to estimate distances, long as not too many hairpin turns!
Ya'll have fun!