The full L test with the blue book cd is the same as the CD that they give you when u take the class.
Plus the blue book is almost identical to the books that they give when u take their course with only one difference which is the Plant stuff. otherwise theyre Identical.
The other books I believe just like u said are the older versions.
I personally didnt study Kaplan books I studied Princeton MCAT and I used kaplan and princeton sample tests .. I think princeton sample test is kind of more close to the actual DAT however Kaplans stuff are great too. Havent take the actual test yet but in practic tests i get around 19 in all subjects and 15 or 16 in reading section lol. I hate reading. "English is not my first Lang too" just like you. lol
goodddd Luck.