Mountain Stream RV Park in Marion, NC is really nice. Sites are a little small but it's a picture postcard campground and convenient to many of the BRP attractions. Loved the owners.
Sherando is great. With no reservation don't count on getting a site on a friday or saturday night during the summer. Show up mid week and you're fine because with your small trailer you can fit in many of their tent section sites - We did that one year when we had our 17' trailer and that section is beautiful.
Of course there're the National Park Campgrounds - Lewis Mtn., Loft Mtn, Big Meadows.