Its better to get the content from SANS since questions can be centered around what you saw/learned in the course not the Practical Malware Analysis book. There are quite a few tools covered in SANS that are not even mentioned in the Practical book. I have the practical book and while its ok, there are certain subjects that are covered in depth during the course (SANS) but only brushed up on in the Practical book.
The Malware Analyst Cookbook covers some document analysis that is in GREM and Practical Malware Analysis doesn't really cover. I'm sure SANS is better. However, I just can't justify ~$4000 on SANS when those two books may not cover all the stuff GREM does, but they come close and do it for ~$70.