Get
PR and the Official CB Math Subject Test guide. (contains two released Math Level 2 tests)
I used this and got an 800. The review in
PR is unrivaled.
I also took practice tests from Sparknotes. (You can find these for free online)
Don't listen to people and get overkill material. Math competition books such as AoPS are not required and are a waste of time IF you're attempting for a good score on the Math Level 2 test.