Noel, when you buy a caravan you have to compromise on most things because it is a relatively confined space to fit the required kit into. Layouts are undoutably down to personal choice but in your situation I would advise you to look at a five berth twin dinette. With this layout you could leave the double bed at the back set up as fixed bed or have a seperate seating area there where the kids can play away from you during bad weather. The two front settees could double as fixed single beds for the kids and in modern vans the centre kitchens and washrooms are very useable with plenty of space. We used this layout when our children were young and it worked extremely well for us.