Just curious, you want RAID-5 but no tape backup ? Is it because you think RAID-5 protection is sufficient or is it that you don't have critical data on your server.
Remember, RAID-5 won't help in the event of a fire, theft, natural or man made disaster that might affect your hardware or data. Plus, anything as simple as deleting an important file accidentally will cause you lo lose it forever, let alone viruses, etc.
Kelvin