The imaging utility that comes with the retail hard drives should work fine.
No, you don't have to use the same size drive as the one you want to image.
I don't know where you read those reviews on the Samsung hard drives, but from what I understand they are hard drives to avoid because of reliability issues. If you want to try something different, go with a Seagate hard drive. Or get another Maxtor, they're good hard drives to use.
Cricket