@Clint - That sounds like an amazing idea! It's impressive how different the terrain in those areas east of Dallas are than the parks I listed above that are to the west.
Both Caddo and Ouachita have dispersed camping available throughout, so there are truly endless options. Researching all of the different camping areas can be loads of fun.
If you want to share, we'd to love to hear back about where you end up camping on your trip later this month!