Saudi Arabia, as the birth place of Islam, the Custodian of two Holy places, Makkah and Madina and as the leading Arab and Muslim country, should get the permanent Security Council membership.
But UN is not that important, what is more important is to increase the power of Arab and Muslim countries and slowly move out of the dependence on current world powers by becoming more self sufficient in terms of technology and manufacturing. UN is just a legitimizing tool for the powerful countries of the world, nothing less and nothing more. When the power equation changes, UN will also change, not before that.