I agree that there is nothing between Vicksburg and West Monroe. Vicksburg has several parks including the Ameristar which provides free breakfast. That would be 350 miles from DeFuniak Springs. To split the difference on to Wichita Falls, a good stop woud be at Tyler State Park just a mile or two north of I-20. That would be about 265 miles from Vicksburg.
A few miles down the freeway from Tyler State Park, I would take US 69 up to Bells, Texas and join US 82 west there. You are wise to take the northern route around DFW. It would be about 250 miles on to Wichita Falls from Tyler State Park.
