I have a similar speced out van to your potential one. Hope these points are relevant. It has a Webasto diesel heater and a proper gas cabinet for my 907. As my previous reply states, it’s been used for coffee making and some cooking since 2017. I’m often wild camping mid winter and have, a few times found my LB battery does not have enough state of charge to ignite the Webasto heater. Which incidentally, is very quiet. Once when 6 below! Not funnyI However, if you can crawl from under the duvet in those temperatures the van heats quickly once the kettle is boiling and I’ve left the gas on trickle afterwards…with proper ventilation and a CO2 meter. I’ve been carrying a spare for ages now but it just goes on and on. My fridge is compressor only so not a drain. Never had much problem lighting the galley stove in low temperatures. Usually it was down to the actual ignition switch but easy to sort with a lighter. My vehicle is kept in the centre of London and is also used as my local runabout and shopping trolley so not good for the DPG but as myself or my son travel around the uk multiple times during the year the system gets a regular good blow through and has never been a problem. Lastly, I did consider the LPG option but I already have two underslung 40ltr tanks for grey and white water but there’s not a lot of room down there. I also have a shower and porta potti installed that can be used inside in the winter even though it’s a SWB pop top (I’ll do a photo tour of all this some time soon to show the cynics). What all this means is, if you are having a van converted from scratch, the conversion is your own personal spec for your own personal circumstances and not the convenience of the converter. Of course if you’re doing the work yourself, you can be practical or showy, outrageous or understated. But as personal as your imagination takes you.