Alright!
Honestly I would try to just not use the 12v fridge option. Use propane on the road like 99 percent of RVs do.
12v vs 6v points are mute once you move to AGM. I recommend Lifeline deep cycle in the shape that fits the most amp/hrs in the space. No difference in construction, very low fail rate.
Next would be to review your charging system to minimize generator run time. Solar is great however if running the generator you want 60+ amps at 14.4 volts into the Lifeline. Flooded you want 14.8 volts again at 60+ amps. Other AGM is good too but check the charging specs.
PD9280C - 14.4 voltsPD 9280C - 14.8 volts