The people to ask is Iomega.
Personally, I think you are better off rolling your own:
Although you can buy a complete FireWire drive system, you can also put one together if you are so inclined. It's relatively easy and only requires a Phillips head screwdriver (typically.) You can purchase hard drives separately. This gives you an opportunity to shop for the best prices on a hard drive of your choice. Reliable brands include Seagate, Hitachi, Western Digital, Toshiba, and Fujitsu. You can find reviews and benchmarks on many drives at
Storage Review. Good sources for drives include:
OWC
NewEgg
Buy.com
Enclosures for FireWire and USB are readily available. You can find only FireWire enclosures, only USB enclosures, and enclosures that feature multiple ports. I would stress getting enclosures that use the Oxford chipsets (911, 921, 922, for example.) You can find enclosures at places such as;
Cool Drives
OWC
WiebeTech
Firewire Direct
California Drives
NewEgg
All you need do is remove a case cover, mount the hard drive in the enclosure and connect the cables, then re-attach the case cover. Usually the only tool required is a small or medium Phillips screwdriver.
By rolling your own you can pick the hard drive model best suited for your needs and save paying a manufacturer for putting the drive in a case you could have purchased yourself. Companies that sell complete systems do not usually use the best drive rather they use the cheapest drive.