Congratulations. You have just bought a potential life changer.
We are now on our second seven seater Beach, both with dark seats and parking heater. There can't be a more perfect vehicle for a growing family. There really doesn't seem to be anything it can't do well. The parking heater is just the most amazing option you can have. It turns the van into a 365 day a year camper. It's ideal for winter school runs, long cold walks and a multitude of other occasions. Just press the remote fob whilst your having your breakfast and by the time your ready to go it's toasty warm and defrosted.
We have eight grand children and they all love it. We've camped in it, picnicked in it, used it as a heated changing room and beach hut. We've entertained in it, toured in it, been to the tip in it, used it as a removal van etc etc. It makes a great reading room and mobile office as well. We also have the extra two swivel seats so also use it for family holiday airport runs. It's also been used for wedding transport and taking elderly relatives on days out complete with mobility buggy.
The interior is pretty user friendly with wipe clean surfaces. However, for total peace of mind, may I suggest you consider waterproof seat covers with young children. Inka do them and they save a lot of worry. They are well designed and are a very good fit. We also have waterproof mattress covers. The club shop sells both and they aren't that expensive. With these fitted the little ones can do their worst and all you need is a packet of wet wipes. You can even hand wash these covers in cool water and they come up like new.
The only other thing that might prove useful in the long term is insulation for the pop top roof. Without it the roof can get a little damp, cold and draughty in the colder months. There are both internal and external solutions available through the club shop. If you are interested then there are several threads on this forum that discuss both types and their fitting.
I hope you all have many happy adventures in your new van.