You seem to be fixed an the Isata. ??? There are lots of options out there and, if you truly are the minimalist that you seem, perhaps a class B would suit you better than a class C. Also known as van conversions or camper vans, they are all built on a regular van chassis - - overall length usually around 25 to 27 feet. They have come a long, long way in the past few years.
Coach House (Florida based) makes a nice one. They have models built on both the Ford F450 and the Mercedes chassis.
Luxury Downsized Motorhomes | Downsized Class C, Class B-Plus, Class B RVs | Coach House Inc.
(edit: there was supposed to be a floorplan photo of the Platinum 261XL ST here. See it at:
Luxury Motorhomes - Fuel Efficient Downsized Class C (Class B-Plus) RVs - Platinum 261XL )
You could replace the mid-bunks with closets/tables or whatever on passenger side and put a compact recliner facing the TV on the driver side.
Here's a used one for sale with some nice photos.
2010 Coach House PLATINUM 261XL, Estero FL - - RVtrader.com
Road Trek (Canadian based) has almost a dozen models on the Ford, Mercedes, and Dodge chassis.
www.roadtrek.com
My favorite (if I went this way) is the Leisure Vans line up (Canadian). Three models built on the Mercedes chassis and two of them even have over-sized queen murphy beds!
https://leisurevans.com
I especially like this model. It has two separate living areas just to give you a change once in a while and it is amazing what they have done in 25 feet. Lots of options, too. This video is 30 minutes long but it really is informative. The first half is all about the exterior and the 2nd about the you won't believe it interior. (and it has a hitch receiver so you could carry that motorscooter
)
https://leisurevans.com/unity/videos...unity-fx-video
Not trying to push any RV type or brand. More important is finding what is right for you and am just saying there are tons of options. Be ready to change your mind, even at the last minute, if something you didn't know about comes up. I am currently researching 5th wheels and hardly a week goes by that I don't have a new "favorite". Good luck.