Redundancy

Our Second Dell PowerVault 110T VS 80 tape drive died last week, so I've been looking into alternative back-up solutions. New tape drives are starting around $1000, but I can pick up used DLT 7000 drives (70GB compressed instead of the 80GB the dead drives supported, but our tapes will still work; our nightly back-up is under 25GB) for $30. The problem is that they're external and have 68-pin ports, whereas our server only has a VHDCI port. The required cables cost more than the drives, and I'm not sold on the reliability of the used drives anyway. The current direction I'm heading in involves nightly system back-ups to an IDE drive in the server (for easy access), as well as to a networked RAID 1 array elsewhere in the building. On top of all of that, I'd like to back-up our most important stuff (databases, mail stores) to a USB drive that isn't always connected to a power source and will be stored off site. Sound good?