SSL Certificates needed for server behind a Web App Firewall?

Hello,

I’m wondering if our Internet facing website which will be sitting behind a Web Application Firewall will simply need a standard 1-name SSL Certificate installed on the webserver itself? Or if the fact that users will be hitting a front-end appliance may give them a certificate error unless we procure a multi-name certificate or a cert to install on the web app firewall itself.

Any help figuring this out would be greatly appreciated!

Best Regards,
-Matt