insurance under 25 for small campervan (vw caddy)

So I want to get a vw caddy or similar, small van which i can sleep in over the weekend, but im not sure what to insure it as.

should I declare it as a van? technically it is a van so ill be sleeping in it.

is it a motorhome? not really but technically yes, but then ill have to get specialist motorhome insurance, and will that cover commuting?