I just put an odyssey 925 in my 993. But that's about as much with the adapter. The nice thing with the dry batteries is that you do not have to vent them to the outside.
I have always had good luck with WalMart batteries. EverStart, or as we call them NeverStart jokingly. You can spring for the top model that has 3 year free replacement plus 7 year total prorated replacement. Keep the receipt in the car and you can get a new battery anywhere in the country.
Your battery removes with a single bolt holding down the battery at the botom. Check the perimeter of the battery. Also, when you take out the battery, remove the negative terminal first.
Hope this helps.
G