IMO
mgmat 5 quant books do take good care of the fundamentals as well as 600-700 level questions, so if you have finished them, you may take a CAT to gauge ur level
mgmat Advance quant and gmatclub 25 quant tests are what i am doing , so i would highly recommend them...But if money is not a problem for you, investing in jeff sackmann's challenge sets ( 1800 questions in sets with 800 basic level questions and 1000 advanced level) is worth the value.
There are only three material that do have 700 + level questions
1) gmatclub 25 quant tests
2) Questions by Bunnel ( they are pure gold, check out his signatures)
3) Jeff Sackmann sets ( i have the extreme challenge 100 questions and these questions are actually difficult )
hope this expl clears some fog.