You don't need a billion sources for the DAT.
Kaplan's material is sufficient for the most part since they cover just about the basics of everything. The test will throw material at you that you've never heard/seen before no matter what so the best you can do is become really familiar with all the basic concepts and derive the correct answer (which is possible most of the time).
Learn the basics first and supplement them using other sources.
Why you taking third time? Those are decent scores i think, way good..what are the rest of your scores? I took it 3x bcus i was WAY low on all scores. Did you already applied and got rejected with previous scores?