Exchange 2010 Backup Suggestions - Backup Exec 2010 or MS DPM

Greetings.  We are a non-profit, so we've acquired both Microsoft Data Protection Manager and Symantec Backup Exec 2010 (with most Agents - Exchange, AD, etc.).

I am a relative newbie at backup strategies, so for now this is what's in place:

1. Backup of Exchange 2010 SP2 using Microsoft Server Backup to external hard drive, nightly.
2. Backup of our Finance/SQL server using Microsoft Server Backup to external hard drive, manually, once per week.
3. We were backing up our user data on our old SAN from the host to an external drive using Microsoft Server Backup nightly.  We've since replaced the SAN with a new one - no backups in place for that yet.

I'm most concerned with backing up the Exchange server properly and being able to do *either* a bare metal restore or a granular mail user/folder recovery.

I'm thinking the Symantec solution is best, but we do have DPM (I have a bit more experience with Symantec, but not a lot).  If I go Symantec, is it reasonable to create a VM on my HyperV server to install just the management and database and do the backups from there ?  Also, we have an iSCSI SAN.  Does Symantec just use a mapped drive to a share on the SAN as a destination or is there some iSCSI configuration to do ?

Thanks much.
-Stephen