Not sure how much help I can be, as I have never done the coffee van thing. Fuel pump is easy to add. Web search for 12v inline fuel pump will get you started. Best mounted outside vehicle. Check generator can take the fuel line pressure it provides. Long as generator exhaust is external to van, you should be good. Think about what could go wrong and apply common sense. E.g. if a fuel line broke, you wouldn't want the generator mounted overhead. If running on self contained fuel tank, you need to be able to refill easily and without the whole van stinking of petrol. For built in fridges, I would look at local refrigeration engineers or shop fitters as sources of recommendations. Where about in nz are you?
