Hi Thales,
First off, a 660 is a strong score (it's right around the 80th percentile overall), so it could be enough to get you into your first-choice School. As such, a retest might not be necessary. Depending on the Schools you plan to apply to, you would likely find it beneficial to speak with an Admissions Expert about your overall profile. There's a Forum full of them here:
ask-admission-consultants-124/If you do choose to retest, you could pick up all of the points that you're looking for in just the Quant section, just the Verbal section, or a combination of the two. Many Business Schools tend to prefer applicants with higher Quant Scaled Scores, so raising your Quant score would be beneficial in a number of ways. Having 2 months of additional study time is great, although you could potentially hit your goal score in far less time than that. With a Q42, you would have made some math mistakes on Test Day and missed out on lots of 'strategy-based' points, so focusing on those issues would be a good idea.
1) What Schools are you planning to apply to?
2) When are you planning to apply?
GMAT assassins aren't born, they're made,
Rich