Overall, I would take HoZ over Exile, because of the higher Zeal dps.
But if you want that “freeze target”, Exile is a great choice.
The Aura pulse Damage isn’t much of a difference.
With Beast in an +3 Holy Freeze Caduceus, you deal more Zeal damage, do more Pulse Damage and the Aura radius is bigger. You are also more flexible with your gear.
Nosferatu isn’t needed, but recommended because the IAS and life leech, but you can achiev better breakpoints with LOH if needed (also LOH is blue <3).
Gold wrap is also an alternative, because of the +10 IAS but also because it’s blue.