When you fit out your van for living the primary concern will be functionality. Being able to sleep comfortably ranking right at the top of the list. In a real bed at home you can stretch out, get rid of the the kinks and creaks making ourself totally comfortable.
If your Van requires that you sleep in a semi fetal position because the bed isn't long enough, you will never get a good nights sleep. Likewise if it's so narrow you can't roll over to your other side, you'll be constantly waking up to change position.
Make sure how ever you build a bed that you do it so you will be comfortable for the long haul.
Do you plan on cooking in your rig? How about washing facilities? Even entertainment needs to be addressed.
As you layout the necessities of life remember, neat and orderly will not only be more comfortable for you, but will help you address the issue of public acceptance.
Click on the title of this article and you will be taken to a good example of how you can set up your van to address the issues of day to day life while enhancing the value and flexibility of your new address.