We have traveled much of that route over the years; not all at one time, but on various trips. Just a few possibilities:
At Natchez, MS there are two good possibilities for overnight or even a longer stay. Each different, but both good. Natchez State Park is a few miles off the route, but a relaxing place to spend the night. Crossing over the river to Vidalia, LA there is the Riverview RV Park which really is on the river. Natchez is an interesting and historical city.
We especially recommend Nacatoches, LA. The campground there is adequate: Nakatosh RV Park, but the city itself and Melrose Plantation and other Caine River sites are well worth a visit.
US 84 goes on through Rusk, TX and Palestine, TX. The Texas State Railroad runs between them. It is entirely a tourist train now, and there is a State Park at both the Rusk and Palestine ends.
In Waco, we just stayed at the Airport RV which is on the Lake. We had one of the best campsites we have EVER had in almost 20 years of RV traveling. On the other side of the same lake is the Speegleville RV Park. Both of these are excellent COE parks.
Lots more I could say, but this is a start. And I have been almost every way possible between East Texas and Florida.