I can get you from Atl to Chatt. Mile marker 317/318 be sure to stop at the New Echota HQ of the Cherokee Indians for a bit of history. Then in Dalton, on Walnut St is a whole section of outstanding Mexican restaurants, and a pretty good Mexican grocery as well.
Chattanooga has a plethora of roadfood places. Go downtown and you cna choose from many, but I'll recommend a few.
Big River Grille, by the aquarium.
English Rose, best English Tea Room I have ever seen.
Porker's, excellent BBQ place.
Zarzour's. Epitome of roadfood. Off Main St, and only open from 11am to 2 pm daily.
Good luck!