This is definitively something you should be able to implement with PRTG.
The SSL Certificate Sensor can be used for this. As long as the Local Probe or a Remote Probe is able to reach the relevant endpoint (the TCP Socket) you will be use the built-in sensor for this.
Simply create devices corresponding to the servers (For example: sip.contoso.com, sfbedge.contoso.com, etc..) and deploy the SSL Certificate sensor (IMPORTANT: Pointed at the correct TCP Port of the service) on these devices.
You can read more about the SSL Certificate Sensor (and some examples) here:
Luciano Lingnau [Paessler Support]