Stayed in the Beuvelande campsite over the may bank holiday. about 5 mins from Gorey. This is a top class site really friendly and clean showers and toilets. they have their own restaurant and bar which was reasonable and good quality. Not that expensive either. We paid £50.00 for three nights including croissants every morning for breakfast!
You need a permit to take your van onto Jersey. Book your crossing through the campsite as they normally have deals.
You can book the ferry separately through Condor ferries though. but remember to ask the campsite to organise your permit.
http://www.beuvelandecampsite.com/camp.html" onclick="window.open(this.href);return false;
Enjoy!