There's also the MEP-017a, which is a 5kw gasoline. I don't know what kind of loads you're planning, but unless you're running massive lights and electric cooking, I can't believe you'd need more than a 3kw. I'm guessing weight and space are a premium also, so a small 3kw would be better.
For camping, gas-driven is probably a better type to pursue because they can be very easily adapted to run on propane or natural gas, propane already being prolific and easy to transport in the camping world. They're also easier to quiet (commercial ones, at least).
If you don't bring propane, you'll have to bring a fuel supply anyway, in which case, diesel will be more efficient.
None are quiet, though. Unless you're camping out in the wilderness alone, any mil-surp genset is going to really annoy other campers.