Hi there,
You'd need the Hyper-V agent that Backup Exec 12.5 has. This would allow for GRT restores and backups of your VMs.
Along with that, you'd need an agent for the Exchange VM, and 2 RAWS (Remote Agent for Windows Servers). Just double-check on the 2 RAWS agents...I think that the Exchange agent ships with a RAWS agent as standard, meaning you would only need 1 then.