Thanks for you reply
I was looking at a coastal area preferably south
It would b used for family holidays and weekends and does not need to be available all year round
'fraid you're going to have to Google all the sites in your target area(s) to see if they accept year-round installations. Some may well accept, but be closed October-May; others MAY accept and be open all year round.
You need to identify when you anticipate using it. You also haven't made clear whether you want to relocate your existing van or buy similar over here. If the latter, you may prefer to consider a comfortable touring van, according to your needs, and park it up in a Garage Mort for when you're not using it.
If it's a veritable mobilhome you're looking for, already installed, you need to be aware that there will be no "rates" to pay as such, but there will be an annual site maintenance charge, plus consumables, either based on an individual meter or on a daily "forfait". There are two ways to buy: one is leasehold, the other is as share-holder. In either circumstance you are bound by majority vote, plus probably other constraining clauses, as to what your obligations are and as to how you can use the installation.
Be wary.
Hils