Which DVD is Correct?

[kresener]

I just bought a 2003 4.6 X5, my first car with nav, so I'm a bit of a beginner...
I currently have software version 4-1/12 and my dvd is 2002-1.
I'm searching on ebay for a newer version of the dvd, and see several available, but have heard that I need to make sure that I get a "high version" and am not sure how to determine if a particular dvd is the "high version".
I was hoping to just purchase the newest version of dvd I could find at a reasonable price, like 2007.1 or 2007.2, get the v29.1 update as well and perform the update procedure as I've read here.
Should I be concerned that I may buy a wrong version of the DVD, or will they all work for me? Also have noted that some of the same versions have different pictures on the dvd, like a desert road, or a road by a lake or ocean. Is that normal, or an indication of some someone trying to pass off an older or incorrect dvd?
Thanks for any assistance or pointers!