Seeing as you are taking a relatively short vacation and are going to be driving high mileages, I would stay away from renting an RV. Look into renting a minivan from regular rental agencies (Enterprise/Hertz...) and stay at hotels. You can find hotels everywhere, especially at interstate exits. Hotels are plentiful and cheaper than those in Europe (think $120/night for a decent hotel - Hampton Inn, HI Express....).
You'll need 2 rooms for 5 people and you get free breakfast.
The minivan will give you better choices to visit places (think of driving a RV through the streets of Charleston versus a Minivan), parking will be easier, fuel economy will be better.... and you don't have the stress of driving to a restaurant or having to cook in the RV.
If you were doing a 2 month trip across the US, then I would choose the RV but you're only here for less than 3 weeks.
Gerry
