It's going to be very difficult for anyone to come up with a definitive 
recommendation without a bit more information about your environment. Are you 
going to be backing up to tape or disk? What are your remote replication and 
disaster recovery requirements? And, of course, your budget.

I'm probably not the best person to answer this because while I know NetWorker 
fairly well, I have no knowledge whatsoever of NetBackup. My friends who know 
both tell me that NetBackup is more complete out of the box, but NetWorker is 
less expensive and offers better support. I'm 100% confident that either will 
do a good job in your environment.

I do have one question though: Why are your choices limited to NetWorker or 
NetBackup? I'd think that a deduplication product such as EMC's Avamar would at 
least deserve a place at the table.

Good luck. Whatever you choose, I don't think you can go too far wrong.

Conrad Macina