Dave, my 2ct about copying / backups and using an external drive.
I use a simple piece of software that goes by the name of "Traybackup" for backing up various parts of my system to external disks. The good thing about is that you don't need to run a special software to access the backups (e.g. in case you want to access a backup version of a particular file) and it makes incremental backups, meaning that if a source file has not changed since the last backup Traybackup skips copying it. Hence the regular backups usually go like a breeze !
Cheers,
Mark