I'm thinking about replacing the hob/sink/fridge in my T25 (the one in there now is non original

With regards to the gas installation, would a domestic gas engineer be able to plumb it in for me, or would I need to take it to a camper conversion specialist for them to carry out the gas installation? (I've had a look around, but can't find any specific "motorhome gas engineers")
Thanks for any advice
