After reading you criteria of what you would like for your Family orientated holiday, i couldnt help but recommend a holiday i recently went on with my family. It was at a campsite in france, with a tour operator. The sites that they go to have lots of facilities to keep the children entertained. You mentioned that costing isnt an issue, however every penny saved is a bonus i imagine. The tour operator had a lot of offers available which you can find on there website