Since I have nothing better to do, I will give you my grand, highly sought after advice based upon my own much looked towards experience:
I think you're really overdoing by using so much study material. Also, how long are you planning on studying for the DATs? I studied for perhaps 2 months every day and found it to be enough.
My studying method was using Kaplan's blue book and which I went over hardcore 4-5 times. I was also enrolled in their on-site and online course.
The only other thing I used was the DAT achiever so I will tell you what I think about it: ABSOLUTELY A WASTE OF TIME AND MONEY!
The DAT achiever is much much harder than the actual DAT. There's no real "learning" that you get from it except a quick explanation to the specific question they give you. As for PAT and QR and RC, it's just way, way, way harder than the actual DATs, so while you are getting practice, it would only make sense to buy it if you're already getting 24-25+ on practice exams that are much more closer to the actual DAT (like topscore).
And, jesus, the 7 exam version? That's like 200$!
Anyways, my 2 cents I suppose