i would recommend you to have a look at
UXCell
they have got a wide range of players and as lattesurf said, the batteries that their players come with are much more better quality than the ones on ebay. i would particularly suggest you the Glacier which has a nokia battery and will give you excellent battery life as well as the option to easily remove and replace it rather than soldering and stuff as in the other players.
they also have a 5$ shipping scheme worldwide.