If you are a member of the caravan club, check their web site under cl sites,you will see quite a few there. We stayed at 'Ford Farm'cl Islandmagee last weekend,lovely site with beatiful views and friendly owners.
I live in northern ireland, so I would advise you to contact the tourist board. They will send you a site book of private, and council owned sites. Most sites are of a very good standard,
some situated in beatiful location.
fred