The LEDs on the GBA AGB-001 are 2 separate SMD LEDs.
See link to picture:
https://dl.dropboxusercontent.com/u/12315555/IMG_170126d.jpg
SMD parts come in strips with anywhere from 10 to 50 pieces or so. There is no way around it because they were made to feed a automatic assembler unit with rolls of whatever SMD part.
It is not particularly helpful but you can always giving your GBA a different color when the power is low.
These might or might not be a good replacement source off the bat:
https://www.sparkfun.com/search/results?term=SMD LED&what=products
The alternative is to order from places like digikey or mouser, problem with them is not everything comes with a visual of the item so it might cost you more in the long run blindly ordering several different LEDs that might not even work.
The LEDs are polar, meaning if you put it in backwards your going to burn it out or worse.