Ive never spent a night off Eagle Rock so I do not have any advice in regards to sleeping. Though, you're hitting the Ouachitas at about the best time of the year - the leaves should be starting to turn. If you could push the trip back a weekend or two, you'd be very rewarded with a nice colour show.
Most hunters are still down though archers will be out in full swing. Also, some muzzleloaders may also be staking out ground as their seasons begins on the 17th of October. Do wear some orange.
I'll be on the OT that time too. I'll be doing Hwy 9 to Pinnacle State Park. We wont see each other, but I'll think of your trip and wish you rootless treads!