Is the Kaplan 800/Advanced required?

Hello everyone! I'm preparing for the GMAT at present and am taking up the test on September 23rd. I have been preparing using the Kaplan basic version, the Official Guide and the Kaplan Math work book. I just started my preparation and am currently purchasing the material which I believe I'll require for practice.

I have purchased the Manhattan SC, CR and RC strategy guides (thought I haven't started using any of them as yet). I'm planning on getting the OG Verbal and Quantitative supplements, and another Quants book which is sold in my city. I'm fairly confident about Quants and I'm not too bad with Verbal. I'm aiming for a 650+ score, preferably 700+ if i can manage it.

My query is whether I will require the Kaplan 800, considering the number of books that I'm using. Since many people say that it does not actually contain questions that are of the 800 level, can anyone tell me whether it will be useful practice? I would like to work with the toughest questions and if not the Kaplan 800, which other book will provide me with such questions?

Further, if anyone says that I require the Kaplan 800, I would like to know whther the Kaplan Advanced book is better structured than the Kaplan 800 one. Since I live in India, I need to place an order for the book, which will take 20-25 days to arrive. So I need to decide now as to whether I need it.

Hopefully someone has the patience to go through this and answer my questions. Thanks a ton in advance!