I’m not familiar with the m200 so don’t know how it compares to any of the others. I started out with a brand new Fuze (which is a fantastic device btw) and then kind of worked back downward with some refurbished Sansa players… e280, c250, Express, and then recently the View. Of the bunch, the View and the Express (particularly the Express) are the most problematic.
As for getting audiobooks to play in the correct order… Unlike some of the other older players that simply worked with file names, most of the Sansa players use the ID3 tags that are embedded in the files instead. There have been many discussions about ways to get audiobooks to play in the proper order.
The easiest way (unless you have a need to keep things sorted and organized otherwise) is to simply put all the files in one folder and then…
Make sure all the Album Name ID3 tags are the same for each file.
Make sure all the Artitst name tags are the same.
Make sure all the Genre tags are the same.
Set the Track tag numbers for the order to play, 1, 2, 3, 4, etc.
And, lastly make sure the Disc# tags are all left blank.
This can all be easily done with a program called MP3Tag (which also also quite usefull for music files).
Now, if you rip audiobooks that come from a set of CD’s and want to keep them sorted out and organized that way, then things get a bit more complicated and you need to then also make use of the Disc# tags. Some ripping programs automatically can do it, but often you end up having to use something like MP3Tag to straighten things out.
For a multi CD set then the Track and Disc# tags would need to be done like this
For the first disc:
Track 1 Disc# 1
Track 2 Disc# 1
Track 3 Disc# 1
etc.
For the 2nd disc:
Track 1 Disc# 2
Track 2 Disc# 2
Track 3 Disc# 2
etc.
I don’t know if these methods will work on an m200, but they do on the Sansa Fuze.
BTW the column to display the Disc# is not turned on by default in MP3Tag, so you have to change the settings for what columns you want to see. Also, by default MP3Tag comes set up for ID3v2.3 UTF and most of the Sansa players do not like UTF. So, that setting should be changed to ID3v2.3 ISO instead. That seems to work best for just about all the Sansa players.
You can find a lot of info about how things work for each of the Sansa devices in the various forum posts. And, of course, there’s always the Search box in the upper left corner of any forum page to help find things (usually you’ll find way more than you are looking for that way LOL).
Good luck with your Sansa players (although I highly recommend either the Clip or the Fuze, those are currently the best Sansa products).