[gearhead]

On 190 near Jasper TX is Martin Dies State Park and Sandy Creek COE on Steinhagen Lake (Dam B). Further East near the intersection of 190 and 165 at Kinder LA. is the Coushatta Casino RV Park. It's the typical RV park, but a somewhat nicer one. A little north of that at Woodworth LA is Indian Creek Recreation Area. I've never stayed there but have driven through a couple times. That would be my first choice in the general area of Alexandria, LA.
If you want further north and east you may check out Poverty Point State Park near Delhi, LA., just off I-20.
I'm somewhat familiar with east Texas and Louisiana but not 63 or 28. Unless you are referring to the 63 at Livingston LA. If so, there is Lakeside RV park, a nice RV "Park" just south of Livingston on 63. It's one of our preferred stops headed east.
A little beyond your destination in Vidalia is Riverview RV Park. Nice to watch the traffic on the Mississippi.
Closest place I know to Jonesville would be the RV park at Paragon Casino at Marksville. It's a nice one but I avoid it because the roads around are so bad.
I've run those roads around Catahoula country and there isn't much to choose from.
edit add: Chicot State Park and Crooked Creek Recreation Area are in the area. I haven't been in either though.