Such beautiful NPs! Wherever you end up, remember that highway 180 is the only viable route in or out. The southern route, through Sequoia, is extremely narrow and winding with hairpin turns. I think there is a length restriction in place, also. Sunset Campground is actually in Kings Canyon NP, and is one of our favorites, as is Azalea in the same area. And we also love the Cedar Grove area, down in Kings Canyon, but we've not taken our 23' Airstream down there. The very narrow campground roads, with big trees and boulders to navigate around, are very "tight" for larger trailer+truck setups. Towing with a shorter SUV would be easier. Have a great trip !