I have one of these ETX-30L batteries in mine:
http://www.dekabatteries.com/assets/base/0278.pdf
I have had it for about a year, mounted on its side with a battery maintainer on it whenever parked in the garage, and it has been doing great for summer and winter use.
Be warned, it is a lot smaller than a regular battery, so you have to fabricate your on hold downs. If you can't fabricate then just get a big heavy Optima that fits.
If I didn't have any electricity available, I would get some quick disconnects from Pegasus Racing, and just pull the battery out whenever storing for more than a couple of weeks.
I had two traditional lead acid batteries go out in my race cars, which I attributed to high G loads, so I will never use anything but an AGM again.