Hi vvEricavv,

Naturally, I recommend Kaplan

That being said, I would recommend that you choose one of your sources as your primary focus. The reason I recommend that is because the last thing you want to do is have two warring methods--and thus, two warring sets of instincts--when the test rolls around. I'd stick with Kaplan, mastering our methods and strategies for the various question types. You'll have a ton of resources: OG, the OG Verbal and Math workbooks, Kaplan's Math and Verbal workbooks, Kaplan 800, and the Premier book with its CD. And remember, you don't just want to grind through all of these problems; every problem will represent not just an opportunity to test yourself, but also a chance to review strategies and check your own advancement.

I suspect that, even with six months of lead time, you'll find that this will prep you for the GMAT fully! But if you're still feeling a little hesitant after working through those resources, you'll have Kaplan's (or whoever's) methods down--and then, if you want to use another company's prep as a resource for additional questions, quizzes, and CATs, you'll be able to do so without the risk of being confused by conflicting strategies for approaching similar questions.

I hope this helps!

Eli