Can anyone point me to a list of sources for the typed AC bonuses?
For example a Ring of Protection provides a Deflection Bonus, and so does the spell Holy Aura. What else provides a Deflection Bonus?
Is there an existing list, or will I have to hunt down every source for AC Bonuses?
If you want an exhaustive list of what different items or effects provide each different kind of bonus I think you will have to make it yourself. I don't know of any such resource.
The most common types I can think of:
Armor - physical armor (+ enhancement bonus) and force effects such as mage armor
Circumstance - cover; kneeling or prone vs. ranged
Deflection - ring of protection, protection against chaos/evil/good/law, paladin's Smite
Dodge - Dex mod, Dodge feat, haste
Insight - ioun stone (dusty rose prism), foresight
Natural Armor - by creature or class feature (+ enhancement bonus)
Shield - physical shield (+ enhancement bonus), weapon special feature (bill, boar spear, meteor hammer, scizore), feat (Two-Weapon Defense), and force effects (ring of force shield or shield spell)
Size - by creature size
Untyped - defending weapon ability