Qubes OS: A reasonably secure operating system
www.qubes-os.org
Qubes is a security-oriented, free and open-source operating system for personal computers that allows you to securely compartmentalize your digital life.

Tick whonix template and upgrade over Tor when setting up.

Spread and install dino im with setup OMEMO all your friends use qubes with whonix and dino im setup xmpp account (lookup chat on tails although many differences how to create xmpp account) https://www.whonix.org/wiki/Chat OMEMO allows file transfer as well as end to end encrypted chat