Did you look at StrideLinx from Automation Direct?
https://www.automationdirect.com/adc/shopping/catalog/communications/industrial_iot_solutions/remote_monitoring_-z-_reporting
Phoenix Contact has some pretty good choices also..
https://www.phoenixcontact.com/en-us/products/industrial-communication/industrial-routers-and-cybersecurity
Both of those seem like good VPN solutions for ethernet devices but I don't see any provisions for serial or USB. Though maybe serial/USB device servers can be plugged into them.