I don't think that Madara wants to be the juubi jinchuuriki. No, he just wants to be able to CONTROL the juubi. That is why he needs the body. he needs something solid to put the chakra of the 9 bijuu into so that he can control it as his weapon. Think about it, the SO6P, the most powerful ninja ever, couldn't fully control the juubi. Remember that it said that teh SO6P was weakened by the juubi, and therefore couldn't destroy it before he died. That is why he seperated it into 9 bijuu, because it was too powerful to control. Madara would never be able to be the juubi jinchuuriki. He needs the Rinnegan and the EMS to control the juubi in its full state, just like he did with the 9 tailed fox 16 years ago. That is why he needs the body in the moon. Besides, the SO6P created the moon when he sealed the juubi, so that means the ninja world could live without a moon. Not in real life, but in Naruto.