Anyplace to find out more in depth stats?

I didn't see anything in the LoL client itself so forgive me if I missed it. Im looking for a place where I can see a breakdown of champions ive played, kill/death ratios on those champions and the like. Im hoping to use it to determine a more set in stone champion roster for when I hit 30 but ive used so many of the free champions that I don't really remember my performances.

Does such a thing exist anywhere or am I out of luck?