Roy; You need to purchase an power cord adapter to go from 50 amp to 30 amp. Then run your refer and hot water off gas. If your batteries are being charged at a high amp load turn off your charger if possible and charge them later when you don't need both AC's. The electrical system on your MH will take care of the rest. Be conscious of other loads as well, no hair dryers, electric fry pans, coffee pot or toaster maybe even entertainment center keeping every thing to a minimum. There is still the possibility that you still will not be able to run both AC's at the same time because the breaker on the pole won't allow it and may trip especially if both units try to start the same time or the park has low voltage which you may want to check after you get both units running.
ON edit; another thing you can do is close off the bed room area when not in there and run on just one AC. Then before going to bed turn off the main unit and run the one in the bedroom.
I purchased mine directly from TST. They have excellent customer service and you can deal directly with them, at least that was the policy 4 years ago. I recently needed some "O"rings for the sensors and they shipped 20 of them to me free of charge. Can't beat that!
We cancelled our land line several years ago and transferred that phone number to DW's cell phone. Been using the MIFI and then Hotspot for 4 yrs. with great coverage. Only had a couple of spots in the Midwest that we lost coverage. This is a great mobile device but remember that you can only watch a few short video's with out running over your 5gb. Skype and movies will eat up your allowed data very quickly!
The same people that make the "Tric-L-Start" make a kit to do what you need which is a charge circuit to keep the towed vehicles battery charged off the MH's alternator. It's called a "Toad Charge". It has a lot of built in safety features for both the MH and the toad. It monitors the toad battery voltage and as it drops the modual relay closes and parallels the MH's battery to the toad battery, when the toad battery comes up to full charge it cuts back out. If the toad is started while connected or if the MH is turned off it drops out. Easy install but it is another wire to connect. Built in self resetting circuit breakers and all wiring and plugs included. Used one for 2 yrs and never anther dead battery.