In fairness our ideal layout doesn't exist in anything smaller than a static caravan. The OH did not want a twin axle so everyting is then the most suitable compromise.
We have just sold our full awning for the last caravan, yet we replaced it with a large porch awning as we found we only used our last one once in 16 months. It was too much hassle to put up. It is only with use that you can find your idela setup.
Another vote for the Adria 542DT. This gives you the best of both worlds. A fixed triple bunk and a huge end bathroom. The bunks are almost 30" wide. I have seen some vans that are only 20". I would suggest going for a van that is one berth extra than you really need. We are are family of 5 and the 6th side dinette stays as a table so no need to make it up when the kids want to get up for breakfast. We can even use this with 5 round(using a stool at the end) as the Adria side dinette is also very wide. The bunks stay made up and we store our mattress topper(from our front double bed)and quilt rolled up on the bottom bunk. Our kids are 3,8,11. Also the side walls are polyester so no more dings from kids bikes and awning poles. Their shape also stands out.They are also very light to tow (1300 fully laden)
Our last van was the 542uk and that had a side wet room. It was usable as a toilet but the shower wasn't worth having. It would have soaked the toilet. This wasn't a problem as the sites we use have very good showering facilities. The 542DT however has a huge wet room . It is big enough for one adult to shower two children,It is great for getting dressed in. It has a shower curtain that keeps the water off the toilet and the rest of the bathroom. unfortunately you still have to dry the floor though.
Our Geist has fiixed bunks and an end washroom, with separate shower. We've only been away 4 or 5 times and we've only used the shower once, for one of the kids. Because of this, I've sometimes wondered if we shouldn't have gone for a model with the smaller bathroom and more living space...however, there is a lot of cupboard space in the end washroom which we would miss if we didn't have it.
------------- 'In later life, you will be more disappointed with the things you didn't do than with the things you did.' - Mark Twain
I love my huge end bathroom but we don't have little ones to consider any more as they've become quite huge over the last few years. I love having space to go and change in privacy - as long as I remember to pull the blind down.
I suggest going to look at as many different layouts as you can to see what would work best for you. We ended up with the opposite of what we thought we needed
We've just bought an Award Transtar 4 berth with L shaped lounge and side dinette and end bathroom and love it. Separate shower and space around the toilet. Good size wardrobe and cupboard under the sink. Plenty of space to shower and get changed in comfort.
Works really well for us - just 2 of us some of the time, but we also take my partner's 11 year old and sometimes our grandson who's 3.