I know I'm a bit late to the party, but I've also been looking for a high power 5V solution. After reading about how terrible knockoff power equipment can be, I was a bit skeptical about buying what ikku suggested on ebaywhat ikku suggested on ebay.
I found this from Adafruit, which should be a solid product. It's a bit more expensive at $25, but power supplies aren't something to skimp on. You would need a breakout for the plug on the end of it.