Try Hwy 7 north from Hot Springs, then Hwy 10 west, then Hwy 23 to I-40.
Do NOT take Hwy 23 north past I-40 -- the road is closed because of damage after recent heavy rains. Take I-49 (shown on old maps as I-540) north to Fayetteville.
Hwy 7 has excellent views of the Ouachita Mountains, but be prepared for mountain driving. Hwy 10 takes you past Mt. Magazine, elev. 2800 feet. If you take a side trip to the top of the mountain, I would drop the fiver because the road up from Hwy 10 is very steep with tight curves. (The road up from the other direction is less steep and ok for RVs.)
I-49 between I-40 and Fayetteville has good views of the Ozark Mountains, with one long and steep uphill grade.
