Those that want to quit Google Services have a hard time. You will Not be able to live without a PlayStore Account. Using this Google Account comes with many sacrifices.
If you ever decide to get away, you will have a hard time keeping your Apps up to Date or even find paid ones.
My idea, having a simple NC App that allows downloading of apk from Google and offers them to Clients. Maybe even notifying them for Updates. In Return, the clients may upload back ups of their apps.