Lots of good points already. We have 6 small Honda generators that can be bridged as needed. Gas powered and very quiet. Good for parade floats, booth power etc... But low fuel capacity for long term home use.
The big diesels are great for 150kW or more. Some are whisper quiet in low power mode. Typically they use Camlocks. Here's a random example.
https://www.elecdirect.com/cam-lock-connectors/400-amp-cam-lock-connectorsYou would wire these to circuit breakers that snap into your fuse panel. Can be temporary or permanent. Have to see about local electrical codes.
Maintenance is important. For diesel you add a treatment to the tank but also pull the fuel filter and add treatment there. This allows all the fuel to be treated. I don't have any experience with non petrol generators however.