How to AutoProvision User with another User Category

Summary

We are going to have Employee and Suppliers as users. want to assign them seperate notification

Content

How to assign seperate email notifications related to account provisionings so that Employee gets an email from a seperate template but Suppliers get another template email. Infact the requirement is to not send account provisioning email to Workers as they will come through SSO but Suppliers will come from supplier portal so they should get an email and should be able to reset the passwords.

How to achieve this if user category cannot be assigned even before user is created. Can we not have a setup to tell what user category I want to create the user for Workers and suppliers ?