You can use Gmail templates to create multiple signatures for different types of emails.
Create template signatures
In Gmail, click
In a window Enter your signature and edit it as needed.
Clickin the bottom right corner templatessave draft as templatesSave as a new template.
Enter a name for the template signature and click Save.
Continue creating and sending a message or close the window and use your signature at another time.
Optional: Create multiple signatures for different needs (internal, for clients, ...)
Sending emails with template signatures
Open Gmail and click
Clickin the bottom right cornerTemplates.
To insert a template, in the Insert Template section, select the saved template that you want to embed in your email.
Create the rest of the message and click Send.