I have some thoughts on the subject.
One needs to cycle a generator every so often, like once every quarter or so. if you don't the windings can become de-magnetized(or something like that) and basically the generator won't generate electricity.
If you use gasoline, that means cleaning out the unit each time..or you will have old, stale gas, and with ethanol flavored gas, that means lacquer in the carburetor, unless you flush it out with non-ethanol gas. That is a PIA. I have one like that which is how I know.
If, on the other hand, you have the generator hooked up to either natural gas or propane, you can turn a valve, run the unit, draw a load on it to keep it functioning and when done, turn the valve and walk away. Done and done...easy peasey. Nothing to get gunked up. There are even ways to do it automatically.
The only problem with Nat'l gas or propane units is the temperature drop which flowing gas produces. In the winter especially, the flowing gas can produce enough cold to freeze everything up.
If a hook up to Natural gas is available, that would be my first choice. Your fuel supply is always there, except perhaps in an earthquake.
Second choice would be a two tank manifold, a gas expansion fixture and two propane tanks. I would want two 50# tanks. Obviously one fifty pounder is equivalent to two and a half 20 pounder grill size units and that should run a house for a long time, like a couple of days. Also, I can handle a full 50# tank and be safe, but a full 100# tank might be more than I want to fool with. With two tanks, when one empties, you can disconnect it, go get it filled and return without interrupting service to the home.