WD Mybook drives are good, but are expensive. For example, the Mybook Home Edition has USB, Firewire 400 and eSATA
http://www.scan.co.uk/Products/1TB-W...nal-Hard-Drive for a better value drive, consider a Maxtor OneTouch 4 Plus
http://www.scan.co.uk/Products/1Tb-M...2-External-HDD they are both 1TB drives but the Maxtor is £30 cheaper, but at the cost of no Firewire/eSATA. I would suggest buying the WD if you can/will use eSATA as it is very fast. As far as I know Firewire isn't that much faster than USB so if you can't use eSATA, go for the Maxtor.
Hope this helps
Let me know if these drives aren't suitable and I'll try to help.