I would consult your peers and look to the industry for additional feedback. Meanwhile, I would recommend that you pursue the Storage Foundation UNIX path. Just yesterday, Symantec published a new Veritas Storage Foundation 5.0 certification exam that's available through Prometric.
Also, since you're working with NetBackup, you might want to consider the new NetBackup for UNIX exam that will be available April 7th.
Stay tuned to Symantec Certification on Monday or Tuesday for a newly designed website, including full curriculum paths. There you will be able to view in detail the recommended preparation.
Let us know if you seek additional information after you view Symantec Certification on Monday or Tuesday