best value for money battery for camping?

Same sort of set up I use and like you could not be Happier..

I agree that it all comes down to what works in the field, not "on paper" figures.
I could run 2 x Ironman 50L fridges (one on freeze) off a 120ah glass mat battery matched to 2 x fold out 80w solar panels, indefinitely.
That's with full sun (in the Kimberley) and fridges with transit bags in shade. Panel input is more than current draw. Simple!