You can tell that article is a little outdated when they say a gasoline engine needs major overhaul to go 200kmiles. Most now are rated for 300k between overhauls and Diesels are something like 1million.

there are cheap ones out there, you can find some at camping stores or home stores for use at jobsites, next step up people buy those Honda ones and then getting even more $ are the big ones you bolt down and you start to get into Diesel. Even though a deisel one may be better than a gas one you should think about standardization of fuel, if you have a gas car and never plan on getting a diesel then you may be better off with a gas one so you can rotate the fuel and burn the older in your car.
You want to first decide on what you need/want to power, trying to do the whole house require a large generator.