Hello OT,
If your intention is only to use the battery for a caravan mover then a starter type battery should be more than enough.
When you consider the usage a mover typically gets, it is quite surprising how little power is used.
Just as a rough estimate, the average current used by most movers will be about 20A, but it is only used for no more that about 6Mins, so the power usage is 20A for 1/10th of an hour which equates to 2Ah current used. That is the equivalent of a typical caravan florescent light being used for less than two hours!
So you don't need a large capacity (Ah) battery, but you do need one that can produce a decent surge current, as electric motors can draw several times the running current just to start the motor. This surge lasts for a fraction of a second, unless the motor is stalled.
Caravan movers surge currents will by a fraction of the starter motor surge current, so this should be chicken feed for a starter battery
Leisure batteries are constructed differently, and they can only produce limited surge currents. Generally the 85 and 110AH leisure batteries can produce enough for movers, but of course they are also used for running other other items, so they need to be bigger.
As for charging, Starter motor batteries do not like standing with low charged states, and of course normally in a car they are recharged quite quickly when the engine runs, But considering the small total amount of power used by a mover in your application, it is likely to be quite satisfactory to leave it off charge whilst you are on holiday. Just ensure it is recharged when you get home, and again before you intend to use it for the next holiday.