my setup if i go sara with 1 other person :
Armour : battlemage robes set, SoL, ely spirit shield, ragefire boots, amulet of magic (t), ring of vigour, sara Arrow, sara/zammy cape
Inventory : Death + Soul + Blood runes obviously, 8 mage potions, 1 super restore potion, 2 sara brews, ferocious ring, 13 manta rays
you'll stay a long time so 8 mage pots is a must. The restore pot is for emergency prayer refill, sara brews is for getting that high defence (first pot sara brew then mage pot), You'll get manta rays as a drop from the minions so that's why you take so little.
Use the blood barrage on the minions when sara boss is standing near her. Guide sara boss to the minions to do this efficiently.