Hi Helen and welcome to theforum good advise has been given here so far, but may I be bold enough to say try and do you deal with a dealer ,there have been some purchases made on Ebay and Gumtree that havnt been quite up to standard.
Also if you go to a dealer you can go for the throat and get most of the things thrown in free ready for your first trip away,and its great fun setting up your van.
Good luck
Sir Roger