We recently were on that route....twice......and circumstances led us to stay at the Municipal Park in Hope, AR.
They have two 50 amp hook-ups and many 30's. It is peaceful and not to hard to get to, though you need pretty good directions. If you are interested, let me know and I will tell you in detail where the 50 amp hook-up is and how to get there. Their fee is $15.
We used it for an overnighter. We went through the same problems as you. There aren't good choices in that area. There is a place in Arkadelphia, but we weren't too sure about it.
Don