It is possible. But for 6 people it will be a bit difficult. Many companys do larger people carriers / crew cab vans, but most dont allow this size vehicle abroad. Ive hired a Transporter and a Galaxy the passed 3 years for a eurotrip / climbing holiday. Arnold Clark ahave a category for Transporters, Vitos and Frafics that would probably be your best bet. I also know that National have a good few Trafics in their fleet just now. As for paper work all you need is your passport / ID, drivers licence per driver and the printed hire document you will be eailed by the hire company. As long as you can get a suitable sized vehicle its a piece of p*ss. Just try avoid as many toll booths as possible 😀 if you have any questions regards the hire, drop me an email and i will see if i can help….