My friend and I have had this discussion before. You trade whatever it takes to bring Lebron in. I love my Rockets, believe me. But I would definitely trade Harden and Howard and Parsons, shoot, anyone else too if I could get LeBron James to Houston.
You'd have the best player in the game, but you'd be left with crap for starters + rest of the bench. It would be another Cleveland situation, except this time, not even LeBron can carry a crap team through the gauntlet of Western teams. If we were in the East, it'd be a different story though.