GMAT Material - Under budget

Hello,

A collegue and I will be preparing the GMAT exam during the summer. I thought it may be useful to buy the preparation material now with the intention of getting familiar with the exam structure and in the meanwhile, if not do some specific preparation, at least increase my awareness towards details that may result useful for the GMAT exam. E.g. Phrase structures or obtaining the main argument of texts'.
English is not my mother tongue, and considering that even native speakers find it difficult to secure a high score in the verbal section, I understand I will need to put in a fair amount of extra effort in this section if I want to succeed in the GMAT. With no further delay, my questions are the following:

1) Is there going to be a new edition of any of the GMAT Prep packages? From what I've read so far, it seems like the MGMAT is the best preparation package at a reasonable price. To be more exact, of the Manhattan GMAT Set of 8 Strategy Guides.
2) For those who have studied with a partner; do you recommend us to buy two copies of the same book or buy different ones and exchange them?

My idea is to start by acquiring the following :
- The Official Guide for GMAT Review, 12th Edition
- Manhattan GMAT Set of 8 Strategy Guides

Then take a few mock exams and see in which sections I need to work on the most, and buy some specific material.

P.S. I am in the last year of a bachelor in Business Administration.

Thanks in advance,
Guillermo.