My thoughts on the battery, would be to just spend the money and get the Canon brand. I have twice attempted to purchase generic batteries for my 1DMKII, both times the orders were cancelled by the vendor for recall issues with the batteries. And I have read to many threads about the generic batteries not fitting properly. I have no problems buying the generic for my 20D or Canon camcorder, but on a $3000+ camera. I'll get the real thing, and get the proper fit and dust and weather seal. Besides, the Canon battery lasts an incredibly loooooooong time. I had well over a thousand+ shots, and the battery indicator has never moved from a full charge prior to doing a refresh. Do a search on ebay, I have seen some good prices on new Canon OEM batteries there for around $100.
Just my .02
Mike