Any top GMAT company's curriculum would be sufficient - there's rarely a need to reference multiple content guides. (Of course I think Manhattan GMAT's resources are unparalleled, but I'm biased!).

The most important resource that you'll need in addition to strategy materials, though, is the Official Guide (OG). It doesn't matter which edition you use, but you want to make sure you're practicing from real GMAT questions. Here's my advice on a study plan:

- First, take a practice test (either from GMATPrep, or any test prep company). This will be your diagnostic. Analyze it in a lot of depth, and ask yourself - In which areas were you weakest? Strongest? Fastest? Slowest? Decide which topics and question types need more of your time and attention.

- Study topic-by-topic from strategy guides, and then practice each topic with OG problems. For example, read the chapter on SC subject/verb agreement, then go do a set of problems in the OGs that relate to that subject (you can find a master list for OG 13 in the back of MGMAT's SC guide).

- Once you've covered all of the topics, practice your skills with random timed sets and practice tests for the last 2 weeks before the test, so you can practice your pattern recognition skills.

- Analyze your data from the random sets, and go back to any topics that need extra work.

Good luck!