Nokia 8.1 has a single speaker with smart amplifier.
In the official packaging of Nokia 8.1 - you will get your Nokia 8.1, USB Type C cable, Power adapter, Headset, Quick start guide & SIM door key.
Yes, Nokia 8.1 does have the EIS. It also has OIS also.
Yes, Nokia 8.1 does have the 3.5 mm headphone jack. It also has Bluetooth A2DP support.