Boxster S Battery Help Please

[bugley]

Brand new to the forum and relatively new to Porsche. Glad to finally be here.

We have a 2006 Boxster S that has sat over the summer and the battery is dead. Got the unit out of the car, tried charging, took some charge, brought to the auto parts store and it has a bad cell.

Called local dealer and they want $275 for a new one which I find a bit much so I guess my question is in two parts:

1. What is a good alternative to the OEM Porsche battery?

2. Once I get the replacement and put it in the car, or prior to doing so, is there any mystical encantations or anything special that I need to do prior to hooking it up?

Any and all help would be appreciated.