Maybe one day when there is better theorycrafting this will be disproven, but for now, with my arbitrary weights, this appears to be the best?

Black Mage
Rank: 1
  • Weapon - Allagan Scepter/Ancient Buckler
  • Head - Sorcerer's Petasos
  • Chest - Sorcerer's Coat
  • Hands - Allagan Gloves of Casting
  • Waist - Allagan Rope Belt of Casting
  • Legs - Allagan Breeches of Casting
  • Feet - Allagan Boots of Casting
  • Neck - Hero's Necklace of Casting
  • Ear - Allagan Earrings of Casting
  • Wrist - Hero's Bracelet of Casting
  • Ring - Allagan Ring of Casting
  • Ring - Hero's Ring of Casting
Accuracy: 121 Determination: 27 Critical Hit Rate: 150 Spell Speed: 140

The best relic set comes in at:
Accuracy: 114 Determination: 49 Critical Hit Rate: 135 Spell Speed: 131