Hey zerotoinfinite,
MGMAT Quant books are quite good for covering the strategies needed for 700+ score. Personally, I like those books very much as I am constantly scoring 46 to 49 in Quant in all GMAT prep tests [Including Kaplan,
MGMAT & GMATprep] after studying
MGMAT quant books.
From Verbal point of view,
Critical Reasoning:
Manhattan GMAT Critical Reasoning & The PowerScore GMAT Critical Reasoning Bible both are worthy enough. But these books are very similar in comparison with one another; there is no value in owning both
Sentence Correction:
Manhattan GMAT Sentence Correction or Aristotle SC Grail. But again Choose any one. You can also refer GMAT Club's Ultimate GMAT Grammar
Reading Comprehension:
Manhattan GMAT Reading Comprehension
I hope these infos can help you to identify