Where to buy high capacity iphone 4 of battery?

I need to buy a high capacity iphone 4 of battery. I looking for a long time at the ebay and amazon, see a lot of reviews about high capacity iphone 4 of battery. But i don't know which one i should buy? Apreciate any help, thanks.

To buy high capacity batteries you should visit amazon.com its the best place. The higher mah gets there. The battery will last longer but also the charging time gets longer too.btw changing batteries on iphones is simple but if your not a diy guy you might damage some parts i recommended watching videos on youtube.

You can't install a high capacity battery without taking the phone apart.
Unless you want a battery case, then check Amazon for good ones.

You can't buy/replace the iPhone's battery in terms of getting one with a higher capacity than it came with.