The first hop, "SSH Client -> Iranian Datacenter" seems extremely vulnerable to surveillance, and would create an incriminating list of people involved. With this discussion in the open, you can bet Iranian authorities are going to specifically look for anything discussed here, so the only viable solutions should have no measurable deviation from normal behavior that would allow them to detect which datacenter was doing this.

To make this happen, you should have a minimum number of connections from inside Iran into the datacenter.

For a small group of trusted people with always on connections, you could just create a linear chain of SSH forwards connecting everyone. For widespread connectivity, a TOR bridge through the path you describe would be workable.