"choose the boot device the image is on" - No.
You boot from the DiskWizard boot disk that you have made using the Bootable Rescue Media Builder. You let it boot up and only then connect the drive that contains the image.
[you might get away with connecting the image drive earlier but booting can get confused when it detects multiple USB-connected drives and can report that there is no boot manager whereas what it has actually done is look at the wrong drive first before the DiskWizard boot disk and then given up]
You can store the image on any drive you want except the one you are going to restore it to. I would not expect booting to get confused by an additional internal (SATA) Hard drive so you should be OK with that - it's additional USB-connected drives that it finds too difficult to cope with.