Is it imperative to have AGM batteries with a solar set-up? Why? Could you not just use 2 6v batteries (not AGM's)? Do they last longer? How much and are they really worth the price difference?
The price difference gets you low maintenance no watering and the ability to have them in a confined space where watering is difficult or impossible. When charged properly they dont gas so they can be used in the living area vs a vented area. They do seem to be preferred when doing heavier amp draws while inverting.
Wet cell GC2 are cheap, effective and good for long somewhat slower discharges such as a golf cart would do. Two GC2 is a common first step in dry camping upgrades.