I bought Trojan T-125's for my first TT as we dry camp about as much as FHU. I sold the TT and they were still going strong 10 years later, when I sold it. Trojans are Flooded Batteries and the simple trick is to never let flooded batteries discharge below 50%. Our new to us TT it wasn't even a choice, I bought two new T-125's and expect 10 years from them as well. If I had the room in your C that would also be my choice but flooded batts need ventilation. Check if you have space and if the compartment is ventilated.
Happy Trails
