Best method of Backups

Ok I just purchased ABR SBS Windows 11 and I'm looking for some suggestions on backups.

we are running
Windows SBS 2011 with Exchange 2010 on the same system.

I understand that Acronis will release an Exchange backup in the coming months which will be great. In the mean time I need a good idea of how to backup my data on my server system.

a little history:
I was a long time user of echo image and it worked great for our usage at the time. I would setup an incremental schedule to a backup location on the network of about 300GB's of data. And then a secondary Scheduled daily backup to External USB Disks which were rotated daily and taken offsite.

And Now:
Our data now has grown to around 800Gb on Disk 2 (data disk) (Exchange being a large part of that Data).
and 181GB used on Disk 1 (local).

I'm not sure how long it will take to make that initial backup of both drives across the network but I can only imagine it won't happen overnight. I'm still looking at options for rotating Drives Daily with Full Backups but not sure how long the initial backup is going to take.

Anyway I'm looking for some suggestions and recomendations to the best method of backups. The Daily offiste rotateable backups are more for insurance and bank purposes. And the onsite backups are more for if someone accidentally deleted something we can go back in time and restore those components.
I know my server on the WAN that was taking the backups before is definitely going to be upgraded to handled this amount of data but not sure how archiving the data is going to work if I need to start Raiding the drives on that system.