cheap and cheerful and prompt delivery.
the battery says its a gtx9-bs but i cannot find this model online. its for a 03 600 bandit.
Cheers
www.2ndbite.com they do batterys, Check em out. 
You could try these guys, they can even fill and charge the battery for you if you are feeling lazy! My new battery arrived with two days. http://www.whitedogbikes.com/bikebatindex.htm
I think Ive got one instock, Ill ave a look 2moz