Well, what the hell would the Lakers need KG for if they keep Pau? In either scenario, both KG an Pau would be paired together.
I do think that if you're going to blow up the Celtics, why not go all the way? Trade KG and Pierce, acquire young assets, etc.
If they decide to go that route though, the odds are looking good that they wind up with either Pau or Dwight. The Lakers just seem too logical of a trading partner at this point.