Backup Solutions

where can I find information on backup solutions. We have an NT 4.0 shop with approx. (25 srvs) one Netware 5.0 file server and one Linux box. We currently use Veritas backup version 7.3 with an 8mm tape system. Our backups take 10-12 hours. Our data is going to explode within the next few months because of a merger and the estimated time for backups will be 18-20 hours. I just need some info on what’s available and any good bad experiences with the systems available. Any help will be greatly appreciated. Thanks in advance.
NextGen
P.S. I’m just a rookie at all this stuff, so please understand my predicament.