This is the way from Florida to Sylva, NC:
Up I-75 to Stockbridge, GA where you take a right fork onto I-675.
Take a right onto I-285 East--the circle bypass around the eastern side of Atlanta.
Take a right onto I-85 North (in the northwestern part of Atlanta)
Take the left fork onto I-985 taking you out to Gainesville, GA.
Keep going straight and the road turns into a great 4 lane--Route 23/365.
Follow the road all the way to Franklin, NC where you'll have to make a right turn.
You'll pop over a small mountain and come down into a town called Dillsboro, NC. Just past Dillsboro, turn right onto U.S 19/74, and Sylva will be a couple of miles--the first town you come to.
By taking this route, you only have 6 miles of 2 lane roads just before you get to Clayton, GA. It's mostly interstate quality roads all the way.
My RV stays in the NE GA Mountains, and I know the area intimately.