Diamond Grading Reports?

Hi Everyone,

Im in the market for an engagement ring and im starting to educate myself about diamonds and how to purchase them. Ive done some reading about the 4C’s over at gia4cs.gia.edu but what im finding is that in addition to knowing the 4C’s there are also several different labs who provide reports on the 4C’s. Can anyone tell me what the differences are between the labs and if there are labs that I should favor and avoid. Given that this is such a major expendature I want to make sure that Im taking all of the necessary steps to get it right.

Thanks!