Any battery where the rates are in CCA and/or minutes of reserve are not well suited for RV use. You would get much more bang for your buck going with one of the big box store's 6 volt deep cycle golf cart batteries. (2 are required to give you 12v)
Capacity on those will be about 220 amp hours. That's a pretty decent start if you are just looking for something to get you from point A to B. They need to be maintained, but dollar for dollar it's about the best option in that price range.
That's assuming you have a fairly standard rig. Ie., electric/LP reefer...
If you like to dry camp or boondock much, have the room for them, and won't suck your piggy bank dry.. then I would go with 4 - 6v batteries.
Picking up a battery tender
would be ideal if a stand alone charger is what you looking for when in storage.
Ditto on the disconnect switch.