I have a standard size transit set up as follows.
6ft double bed, converts into 3 seats round a table, twin hob, grill with cupboard underneath. Sink with external pump from water carrier. Lots of underneath seat storage. Full electric hook up.
It’s also boarded off at the back where I store the bikes widthwise. Either 1 with both wheels on or upto 3with front wheel off Also tools etc fit in there.
Have windows fitted in both side doors and a skylight
Great van, room to cook eat, chill and sleep 2 + dog on the floor with bikes safe in the back.
Use it as my everyday vehicle and getting 37mpg out of it. Will probably never get a car again. Self build by me and my dad.