Geoff, to answer your question, if you need a generator, as we do at times, then for the sake of the electronics in your van you need a good generator.
A 4 stroke with sine wave inverter technology is the best and safest and are generally very quiet in use.
Do not even consider a cheap 2 stroke, they are noisy, need very regular maintainance and can produce huge voltage spikes which would fry any of the sensitive electronics such as charger unit etc.
We use a Kipor Ti2000 which is virtually identical to the Honda, but at a much lower price.
With the cost of fuel, they are not cheap to run, using a tank of fuel in 4 hours at full output use, but they have an intelligent speed control which automatically adjusts the sped to match the load.
Some sites do not allow generators but lots do, and providing you are sensible in its use and not expect to run it 24/7 then it should not cause any problems.