Ibaka or Harden?

Ok so the Thunder are a top of the West with 9 games left and everyone is jelling with each other but eventually down the road is a problem. Ibaka and Harden are UFA in the summer of 2013 and the Thunder might have to choose one to sign. In my opinion it should be Harden because of his ability to score off the bench and his versatilitie. He just to me has more to offer although Ibaka's amazing ability to block shots and his offensive skill is improving within each game. The thing is though Harden should in my opinion be our starting PG because of his ability to pass it greatly and Westbrook  needs to be put on the wing it would just be a great strategy for the Playoffs. Anyway Ibaka is a greaet player but if you let Harden walk away you will regret it. Hopefully the Thunder can find a way to keep both and keep this great core of players so we can win not one not two or three not four or five but six or seven titles in years to come....Just a thought.