Using #Storj and local #Nextcloud (one per machine) is actually quite easy:
!/usr/bin/env bash
# Taken from https://fedoramagazine.org/nextcloud-20-on-fedora-linux-with-podman/.
podman network create nextcloud-net
podman volume create nextcloud-app
podman volume create nextcloud-data
podman volume create nextcloud-db
# MariaDB
podman run --detach \
--env MYSQL_DATABASE=nextcloud \
--env MYSQL_USER=nextcloud \
--env MYSQL_PASSWORD=DB_USER_PASSWORD \
--env MYSQL_ROOT_PASSWORD=DB_ROOT_PASSWORD \
--volume nextcloud-db:/var/lib/mysql \
--network nextcloud-net \
--restart on-failure \
--name nextcloud-db \
docker.io/library/mariadb:10
# Nextcloud
podman run --detach \
--env MYSQL_HOST=nextcloud-db.dns.podman \
--env MYSQL_DATABASE=nextcloud \
--env MYSQL_USER=nextcloud \
--env MYSQL_PASSWORD=DB_USER_PASSWORD \
--env NEXTCLOUD_ADMIN_USER=NC_ADMIN \
--env NEXTCLOUD_ADMIN_PASSWORD=NC_PASSWORD \
--volume nextcloud-app:/var/www/html \
--volume nextcloud-data:/var/www/html/data \
--network nextcloud-net \
--restart on-failure \
--name nextcloud \
--publish 8080:80 \
docker.io/library/nextcloud:20
So no need to use Oracle cloud for this. And instances do not really need to necessarily to sync up given the user count.