If it is any help to you, our first van was a Le Voyageur (Part of Pilote) and at 7.3m seemingly a bit of a beast! You soon get used to allowing extra space for over taking and I found that it calmed my driving behaviour which was a good thing! It had a double bed which moved electrically to give more space and with this van we fell in love with motor-homing. Le Voyageur were fantastic in their servicing and guarantee work (at the factory) in France. Tears flowed when we changed to an 8.3 van (Niesmann and Bischoff) which after five years has proved to be comfortable and reliable. Twin beds now, but that doesn't stop my wife from whacking me when I snore!!
So, when you finally decide on your layout do consider the "high end" vans, obviously used, but generally better screwed together than cheaper models. Always check the payload available as with more space, more "can't live without" stuff finds its way onto the van.
I should also mention that we live in Spain and the larger van is so much better suited for travelling abroad. We were here in the UK for a wedding in North Devon, and taking our beastie down those small narrow roads was not a lot of fun. Also it generally rules out touring in the UK due to size, so your intended type of use will also affect your decision.
Finally, good luck with the search.
Ainsley