Plz advice me regarding portable HD for my MBP

I mostly use Western Digital Passport SE 1TB drives that I pick up at the local Costco. These are used for Time Machine backups. I keep 1 in the office and 1 at home. I also have drives that I keep as complete bootable clones (using CCC) in case of catastrophic failure. One of the clones was created immediately before I did the Snow Leopard to Lion upgrade. The other clone is Lion, and updated on about a weekly basis. This drive is a Seagate Free Agent 750GB with a FW800 interface.