Configure 3 FXO (SPA3000)/Voip & 1 GSM gateway with xCALLY contact center

We are looking to skillful guys to Configure 3 SPA3000 devices & 1 GSM gateway with xCALLY contact cloud center (Asterisk base call center system). The job will be mainly sitting the devices to be connected with xCALLY systems using the sitting parameter of xCALLY GUI. * the xCALLY is hosted in VPS @ germany. * The VPS @ germany is connected to NordVPN. * again: VPN gateway connected to NordVPN service * the GSM gateway &3 (SPA3000) Cisco VoIP connected to Internet over a VPN Gateway * This granted GSM & Cisco gateways to see the server in Germany * Server in Germany connected to the VPN gateway via RASPBERRY B3 computer that is connected to the same switch with all VoiP devices. We expect to configure the above VOIP devices with the xCALLY for both Incoming & outgoing calls. We could give access via Team Viewer so the user can access the Raspberry to brows the configuration webpage Using VNC Viewer for each device. in simple way of connecting: Internet (VPN) => switch => RASPBERRY+4VOIP gateways => VPS + xCALLY Looking for your proposals.