Backup Exec SAN style backup

Hi,

I have the below scenario and need to know the SAN backup.

2x Physical server with 2xExchange servers clustered need SAN backup

2x VM host's running 2x SQL db need SAN backup

Do i need 4 Backup Exec core licenses along with 4 Application & db and 2xagent for VMware ?

or will I need 1x Backup exec server with 4 Application & db and 2xagent for VMware ?

I also have NAS storage from EMC. Is it need any license?

Thanks