Two Fireball Wands (Double Wand Wielder, Wand Mastery):
Swift Action: Quicken (+4) + Twinned (+3) + Intensified Spell (+1) + Empowered (+2) + Maximized (+3) = 13 (charges) * 2 Wands + Spell (Primary Wand, 1 Charge) + Spell (Secondary Wand, 2 Charges) = 29 Charges, 2 Wands, 4 Fireballs
Standard Action: Twinned (+3) + Intensified Spell (+1) + Empowered (+2) + Maximized (+3) = 9 (charges) * 2 Wands + Spell (Primary Wand, 1 Charge) + Spell (Secondary Wand, 2 Charges) = 21 Charges, 2 Wands, 4 Fireballs
Total 50 charges, between 2 wands. Normal Fireball does 10d6, Intensified Spell Raises to 15d6, Empower Raises to 22d6
8 (Fireballs) * 22 (dice) * 6 (Maximized) = 1,056 points of Fire Damage.