Hi Lee (and Sue) - welcome!
Where to start suggesting vehicles?
How important are those other two berths? And do you need legal (belted) seats for them to travel in?
Are you thinking in terms of a Panel Van Conversion (built "inside" the original van, perhaps with a high top or elevating roof fitted) or a Coachbuilt (like a caravan body, on a chassis-cab base)?
What level of kit do you want onboard? In the "kitchen, you can have a full cooker or just a couple of burners. In the "bathroom," a separate loo and shower, or the two sharing a space, or neither - just a portable loo in a cupboard!
Partly depends on whether you lan to use full-spec campsites, or go "wild."
Are you happy to make up a bed every night to save space, or do you want a fixed ready-made one?
That's probably enough questions for a Sunday night, but maybe gives you a bit to think about!