We are tent campers so I can't offer too much advice as to electric sites. They're all in the same general area though. Just an FYI that while two of the trailheads (Limekiln and Walnut Ridge) are close to the campsites, some of the others are not (those near the north gate). Granted, the two trail systems do link, it makes for a pretty long loop.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher