41 Mana sources, 38 lands 3 rocks. Only around a 70% chance of having Nahiri out on turn 5. Adding 3 plains gets me to 77%. To make it roughly 80% probable I have mana for Nahiri on T5 I need 45 sources (may be able to drop to 43 due to several of them producing 2x mana.
15 equipment (tutors) is 90% probable to have at least 1 by turn 5.

Quarantine field to go in over one of the instants/sorceries. Has the bonus of being a enchantment tutor target.