All official warranty models include accidental coverage and some free data offer with Jazz 4G.
Accidental coverage basically covers you for 'accidents'. If you break your phone by accident, you have to go to the Service Center, fill out a claim, describe as best you can how the accident happened, and give them a few days to get back to you, if your claim is approved, they will replace your screen with an OEM part and return the phone to you. However, many people have said this entire process takes very long and sometimes they can refuse your claim, in which case you'll be required to PAY the full amount for a screen replacement, which for an S8 is very costly.
Entirely up to you, I bought the model with no local warranty, used it for 4 months, sold it at a great price and had no issues with the phone.