Two Gateways in different networks

Hello everyone. I would like to ask for advice about Ignition network architecture.
Customer ask for two servers (Ignition Gateways). One would be in secure network and gather data from PLC’s. Second would be in DMZ, collect data from RTU’s over GSM network. Gateways will be connected to each other. Users should have access, by Vision client, to both Gateways.
Thank you in advance.