Last year I bought a 2.8kW Chinese gas generator for £250, new. It's good, But the regulator is very primitive.
It will run straight off the standard gas regulator , but there is a "thingy", which I can only call a regulator, on the gas input to the genny. It doesn't regulate in the same way as the main regulator, it only allows gas through when the engine is running (by means of the inlet vacuum generated, if the engine stops, the gas flow stops) and provides primitive mixture control.
If the genny isn't under much load , it "hunts" (technical term old petrol heads will understand) a lot because the mixture is too rich, but if you weaken the mixture (knob provided) it stalls under load and is a bitch to start, solution= put up with the hunting! It will be interesting to see how it fares in the examination next year.
Mine lives under the cratch floor, it needed a bit of angle grinding on the frame and an exhaust outlet in the hull, but it's out of the way and tolerably quiet for a quick ding in the microwave or battery boost. It can be started with a decent battery drill on the crankshaft end if you don't like pulling string.
When I get the installation finalised, I'll post some pictures.
I think the benefits of gas far outweigh the few minor snags I've had.
A £150 conversion kit must be quite hi tec, I'd like to see one in the flesh.