I drink green tea too myself, but I also really LOVE my green tea extract I got from GNC... I put that in a fruit smoothie, in juice or just under the tongue - tastes awful straight like that but you get a wowza feeling, really boosts you up. I do that before I exercise - it really helps a lot for me.
I'm not a doc, but I would imagine your money would be better spent on the extract if you want something potent. And I don't believe it helps burn fat necessarily, I do it for the antioxidant properties of it, and the energy I feel. And green tea - warm or cold - is great, and counts towards your water intake too. So put some over ice in a water bottle, and squeeze a little lemon or orange in there - yum. So good.