"powerful projectile weapon vs extra 14 points of magic"
If that is the determining factor, level 1 of Alchemy will let you mix
restoration potions, and a few extra pieces of loot traded will get you more potions. With a better ranged attack, you will also not need to rely on Aura of Guarding or Restoration as much.
"it's gonna be pretty tough to find another item that will provide me an extra 14 points of magic"
I found an amulet at the bottom of the catacombs with +40 Vitality and +40 Magic (took a bit of re-loading). Much of my equipment had either a mana or intelligence bonus (at the end of the game I had 574 mana points, but only 30 without any equipment on - my vitality was 1260, or 444 with no equipment).