Andre iguodala or trevor ariza?

I'd say it depends on who you pick. If that player can shoot (melo, KD) then id go for Iggy to gain versatility and driving ability. If on the other hand he is a mediocre shooter (LeBron) id go for ariza to spread the floor better (not that he's such a great shooter). Ideally you'd want a Ray Allen type of player next to LeBron.