First thing to consider when looking for local generator power when your grid is down is whether you need continuous power, or only at intervals of various lengths of time.
Here in NH, the power goes out 90% of the time during winter storms.
So the home needs enough heat to keep the water pipes from freezing, especially if you have forced hot water heat; which also means you need your furnace igniter and blower running and its zone pumps working. But you can do that for an hour two or three times a day and leave everything off the rest of the time.
Don't need to keep the fridge and freezer running as everything goes outside on the porch in coolers and Mother Nature puts the chill on.
So for occasional, emergency use, a PTO driven generator is probably just fine.
If you have medical problems that require constant power, get a dedicated
generator, and a big fuel tank that can keep you going for a week minimum.
In both cases, unless you really know what you're doing, have a licensed electrician put the wiring in from the generator to your house. And make sure there is a mains to generator cut over switch; otherwise you're going to have the power company charging you big fines.