You can search on Caravanfinder website by MPTLM. Hit the advanced search button and scroll across the tabs to put in your requirements. They don’t cover every van for sale in the country but you will find some makes and models to explore further. Older Swift Alpine 4 for example
Mel
Bailey 460/4 but check rear floor from underneath for water damage. Adria Altea 430 <2011 1100kg. Likely to be more watertight but appliances may not be duel fuel, mine has electric only HW, gas only heating and no oven. Altea comes in few different layouts, get one with kitchen on bed side as it has bench extension that folds over bed.