Sanctuary from weapon or shield is only available if you choose melee as I said. Should also point out that using free auras on equip lacks any boost by increasing skills with gear or using skillers, you're limited to the level it says it is. Having multiple auras makes up for that to a certain degree.
Sanc/Holy fire:
1 Holy fire (prereq to Conviction anyway)
20 Fire res
20 Sanctuary
20 Conversion
20 Conviction
20 Salvation
Using an exploding bow with 1 in holy fire and maxing out fire res might work until you get sanctuary up and running. Carry lots of fire damage charms and use fire damage jewels or Ral runes in gear and weapon to make up for the basic holy fire. Then work on sanctuary and synergies until level 85 when you can make a holy fire weapon, be it bow or melee. Brand at level 80 makes quite a nice bow too, it casts an amplify damage curse and shoots exploding arrows, double whammy.
Despite the vast range of skills you can incorporate into the Auradin, it's best not to branch out to too many though because it starts to lose focus. You can never get enough -enemy res or +skill dmg% for all damage types. And you can only have one of your own auras active, obviously