If you are staying for a while and are going to travel to the south from the NY region, then driving would be the better idea because of the scenery. Plan a day or so just for the smoky mountains, they begin in Virginia with the skyline drive and continue into north Georgia. In the summer you might see a bear or two and the trees and mountains are very beautiful.
If you are going to Miami for the beaches you might look into NW Florida and the Gulf Side of the state. Panama City to Pensacola has the prettiest beaches in Florida. Miami is all but been taken over by the Cubans and the Spanish. It might be interesting for a short visit.
If the international scene suits you don't miss the Orlando area, the entire world is represented there during most summer months. Of course Micky Mouse lives there also.
All of the rental cars are automatic and the wheel is on the other side from british cars, and you will drive on the right lane.
The most beautiful part of the country is the west. Arizona is fantastic.
I have lived in almost all parts of Florida with a five year stay in Arizona.
BREEZE