I think for what you want, I would try the HF generator. Its not like it will be getting 1000 hours per year on it...

and the noise?

They make silencing mufflers for ATV's. The one I saw limited the sound to a clicking noise. One word, "amazing!". They are aftermarket and universal/clamp on.
What would such a device do to the engine on a small generator? It would change the backpressure. Would that hurt the engine? I don't know.

I found that you can move a generator away from the camp site, stack wood aaround the unit on the side of your campsite, run a 100' extension cord and it does a decent job of cutting your noise.