Generator selection should start with the destination electrical requirement, not only the kW number.
Confirm nominal voltage, frequency, phase, outlet standard, connection method and starting method. Ask whether the quoted value is rated output or peak output. If the application includes motors or other starting loads, explain that requirement to the supplier.
Keep the requirement in writing and ask the supplier to repeat it on the quotation and datasheet. This reduces the risk of comparing one model using a 50 Hz configuration with another using a different voltage or phase.