Where I can buy a batterie for my Asus A32-N55?

You that I have a asus laptop and the batterie Asus A32-N55 has already told me goodbye. I do not even 25 minutes hard. I've looked at the official website of asus, but no stock and the price seems excessive to me (150 €). A friend told me to take advantage to buy a battery that is better, but ... would be unofficial, right? ? Could use a better one?
? Could you recommend any site that is legit? I'm no expert on the subject, so I come to you.

I've seen some with 8 or 12 cells, with more voltage, etc ... What does this mean? ? Are better? ? Me I can trust?
For example this: http://www.elecachat.fr/a32-n55.html
Or this:
http://www.bateriabaratos.com/a32-n55.html
http://www.pcbateria.es/a32-n55.html
will you suggest me which one of the better battery

Thanks in advance