Wow! I like your Ducato hatchback van! You picked the longest and the tallest body and extended it. That's a huge van! We also have long Fiat vans in the US, but not yet as tall as the one that you have.
I also added a bed recently (pictures are coming). I always wanted to keep an "open floor plan", so that I can remove everything and use the van as a cargo van, if necessary. So, my bed is suspended on cables above the motorcycles, and is also height adjustable. If I remove the mattress and raise it all the way up, I can walk under it freely. If I had the van your height, I probably would have been able to keep the mattress on it at all times.