The layout of the van will likely be the one thing you'll think about the most. Really with this is it what will work best for you. With the small mini van however, I'm not sure how many options you actually have when it comes to this. Most cargo vans are wide enough that you can sleep horizontal across the back. With this van, it is simply not an option.
I also took into consideration the comfort of Baron traveling and what things were most important to me ... extra room for food, the fridge, where water would go and how much clothing I want etc. I ended up taping the whole things down to get an idea of what that visually all looked like before I went crazy and started tearing it all apart. Baron seemed into it already laying where his couch would be.
I did my original drawing and plan at the beginning and sadly I thought I had more room than I actually did. So from my original drawing to the final you can see the changes.
Originally I had planned to build out my whole inside before I opted to buying pre-built kitchen cabinets. It was definitely not the most cost effective, but when it came to making things level and optimizing the lack of space I had it worked out perfectly. There wasn't really options for sliding beds (more on the next post about this) and cupboards with cabinet door fronts was just an easier way for me. I can build as you can see, but I am not very good at exact measurements and this would fail me if I didn't go this route.
In previous photos you can see where I cut all the cabinets to fit around wheel wells and where I cut to fit the sink and counter top in, so check out those posts.
Again no right or wrong, just do what is best for you so you are comfortable. With having such a small van though I think the only real change you could make is building the wall to fully close off the back from the front and running your kitchen behind the seats giving you more room for a bed and also potentially giving you the option of both sliding doors opening. If I wasn't traveling with my dog I likely would have gone with this layout instead. Easier to build and more room, but Baron being 100 pounds would have been so squished in at the front.