I took my GMAT in Oct this year. The 2 key books I used were PR Cracking the GMAT
(2002 ed) and OG 10th
ed. Both books were passed to me by a dear friend in 2002/2003. (The only book I bought was the Kaplan
2005 edition, and that's because I wanted the CD-Rom.)
And I get 700+ for my actual test. Personally, I think the versions of the materials don't matter much. What is important is to get good publishers' materials.
However, for your case, it is a bit tricky since you are taking the "new" GMAT. But if we take what ETS says at face value - that the content of the GMAT is still the same - then I think it is ok with the materials that you have.
You can also check your local library to see if they have newer editions, if you don't wish to spend the money. For course, don't expect that they have the latest editions.