I'd go with an AGM battery rather than a gel cell battery if I had the choice. AGM (absorbed glass mat) are pretty much as rugged as a gel cell battery but they are more tolerant of being charged incorrectly. If you charge a gel cell incorrectly you'll wreck it in very short order. There is no fixing it.

A quality battery properly set up and charged and maintained should last a very long time.

By the way, this is the time of the year that kills batteries in my opinion, not the winter. Heat is a more efficient murderer of our friend the battery in my experience. I think out of all the batteries that I've had die on me a good 85% or more have been in the summer. I remember changing a couple in the cold but most were in the heat. It's just brutal on electrolyte and grid plates.