I use a 1.5 TB external drive that I bought at Costco. It has USB 2.0, 1394, and it's own power source.

The backup software I use is CloneZilla, a Linux distro on a boot-able CD that will exactly clone or restore the entire drive(s). It is quite effective, I have files that date back more than 10 years so I don't want to loose them. Mac is a bad word around here so I don't know if it will work for you, but I think CloneZilla works on "intel based Mac OS"

I have cloned and/or restored drives with various formats without problems, including NTFS, FAT,FAT32, EXT2, EXT3.