For absolute quiet (and "greenness") get a battery "generator". These are not generators at all but just large battery packs with an inverter. Maybe with some solar panels, like this:
This suits the "tech" company image a lot more than any gasoline generator and they are virtually silent. California is going to ban the sale of all gasoline generators in 2 years because they are pollution monsters - the motors are similar to 1960s cars before they had any pollution controls.
Aside from the noise (those little inverter generators are very quiet at idle but the noise really comes up if you try to draw significant power out of them) you are going to have to deal with carrying gasoline around plus remembering to check the oil. Having a thing that sounds like a chain saw humming in the background is really going to damage your "communing with nature" experience. What might not be very noticeable on a food cart on a busy urban street corner with cars and buses roaring by is going to drive you nuts in a quiet forest. Try to get a demo of the generator you want (if you end up buying a gas generator) and make sure that the demo is UNDER LOAD (e.g. connect a space heater) so you will have some real idea of the noise level.
You need to figure out how many watts you plan to draw and for how long and size your generator or battery power supply accordingly.
Not sure if its exactly the same but amazon has this on sale.