I have a TST system, upgraded to the one with replaceable batteries. you don't have to remove the sensor to air the tire. Both systems I've had work well. Battery life seems good.
If you have a built-in water filter that uses a filter canister, check that carefully. If the canister freezes, it can crack and when your system thaws you may have powdered activated charcoal spraying out. Big mess!
I would suggest a 1 ton diesel, with a transmission having at least 5 speeds, with capability of engine braking going downhill. My tv is not a dually, my 5er is about the size of yours, no problems with handling.
I recommend Trojan T-105 6V golf cart batteries. I have used them for years on RVs and boats. Pay attention to the charge, don't draw them down more than 50% and they will last many years. My current set is about 8 yrs old. A good way to compare ...
