I'll be leaving for my tour probably on Monday, heading toward Myrtle Beach then then Baltimore either via the Outer Banks or northbound mainly on US 301.
You will always be able to buy food while on route so you shouldn't sweat too much on what to bring. One thing about entering Charleston.. US 17 north of Charleston to Georgetown has a really high death toll rate. I would suggest sticking to the Atlantic Coast route or at least using US 17 alt which will add miles to your trip but is safer.