Which postage option is best to "guarantee" a parcel arrives safely to a customer overseas?

I can never decide between Registered Post or Pack and Track as they're the exact same cost and one option has one benefit over the other.

Registered Post

+ Signature on delivery

+ Proof of postage

+ Includes coverage of up to $100 for loss or damage to articles posted

- No tracking

Pack and Track

+ Tracking

+ Proof of postage

- No signature on delivery