Hi Jimmy,
Don't keep all the official material for the last. This is because the real learning comes from analyzing official problem. So you would want to denote more time on such questions. You would need atleast a month to solve those problems thoroughly. I would suggest keep exampack for the last to gauge your score as most of questions from exampack are not there in Souvik's file. So don't keep Souviks file for the last. Atleast start working on that atleast a month before you plan to take GMAT.
Regarding the strategy, I would say develop your own. Initially I adopted e-gmat strategy but it was time consuming. I then read Veritas STOP strategy and it gave me good inputs about overall reading. So I took good points from both these sources and developed my strategy.
Hope it helps.