Firstly there is no specific Honda batteries ever made. You can put any good brand like Amaron, Exide, AC Delco, Trane etc.
You can find replacement battery from Satwa car accessories shops, all batteries comes with 1 year warranty so insist on that to make sure so you get original ones.
Secondly dont forget to bargain nice with Satwa boys as they love to hike up price by 50%, so better check in two - three shops and then buy.