[GERGE]

dd actually is the best tool ever to clone drives, it works bit perfect. But expanding the KOBOeReader partition doesn't work in OS X, OS X does not talk in MBR. You have to do that part in a virtual machine like Parallels.

This is the dd and diskutil commands, maybe you could add them to the first post?

To find which drives we are going to clone to and from, diskutil list command is needed. It lists the disks. Then this two commands to take an image and restore it:

sudo dd if=/dev/disk2 of=~/Desktop/KoboSD.dmg (takes an image from the original card)
sudo newfs_msdos -F 16 /dev/disk3 (cleans the new card) (optional)
sudo dd if=~/Desktop/KoboSD.dmg of=/dev/disk3 (writes the image to the new card)

Afterwards it is the same, you only need to use a Virtual Machine. Parallels trial would work well (if they still have trial).