Also, check out the campsites on the coast at Brean, Somerset...several of them with a clubhouse shared by all. Not sure about swimming pools but there is a Pontins there I believe.
Polmanter in St Ives or Trevornick Newquay......2 of the best in Cornwall for what you want......but maybe missing slides but got everything else....nice sites
Don't forget to leave a review of the campsites you have visited this year or last!