I would suggest Davidson River Campground in Brevard. Several close waterfalls, can camp next to river or do some tubing, and many many miles of hiking and mountain biking. Also it is a 20 minute drive up to mountain to Blue Ridge Parkway and Mt. Pisgah. Be sure to check out Black Balsam Mtn.
Hiking in the Davidson River Area
Next suggestion would be North mills river campground in brevard or possibly Black Mountain Campground.
North Mills River Area (http://www.cs.unca.edu/nfsnc/nfnc_fishing/north_mills_river_area.htm - broken link)