Having lived in the Fla. keys were 5 minor hurricanes a year isn't uncommon, but even a minor hurricane, or a hurricane strike up on the mainland will leave us dark for days and sometimes weeks (ANDREW!)...
And having grown up in, and now living in 'Tornado Alley' again,
I've learned a couple of things about generators...
1. You don't need to buy a 'Propane' or 'Natural Gas' specific generator. (also called a 'Genset')
Most of the popular larger brand generators, whether gasoline or diesel, have kits made for them you can add propane on top to make them 'Dual Fuel' units.
This is REAL handy when you don't know which tank is going to get blown/washed away...
2. If you can use the most BASIC common sense when working with propane or natural gas, it's VERY EASY to convert about any generator over yourself.
Remember, generators run at a constant speed, so if you get the mixture right for 'Full Pull', then it will just run a little rich when it's not 'generating', which you should shut it off anyway...
Fuel diffusers and engine shut off switches/valves are EASY to wire and use, so there really isn't any reason someone handy couldn't convert a gas or diesel engine generator for propane or CNG.
3. Buy more generator than you think you need.
Buy as much generator as you can afford, and then get the next biggest model...
There isn't any such thing as a home generator that is 'Too Big', but you can very easily buy one that is 'Too Small'.
4. Advertised Wattage is usually the MAXIMUM SURGE LOAD, and the generator will melt down if you try and run it at the wattage stated on the sticker on the side!
Example, my first 'Hurricane' generator was a 'Craftsman' brand.
Splashed down the side in big letters was "4,000 WATTS OF POWER".
Turns out, that was the peak 'Surge' rating, anything over 2,500 watts output and it would throw breakers and eventually melted the solder out of the terminal connections in the generator.
5. Mounting/Storage/Hookup location is everything!
The generator won't do you any good if it's been under water for 4 days, or the outlet where you connect it is under water!
6. Don't be afraid of a deal.
Very low hour generators can be had for cheap right now because of the hurricanes down south, and the flooding in the midwest.
Remember, every one of the larger boats had a good sized genset in it, and every one of the larger RV's that were ruined in the hurricane or floods had a good sized genset in it!
The salvage places are full of good quality, brand name gensets with low hours on them right now for dirt cheap prices!
7. DO NOT BUY LAWN MOWER ENGINE GENERATORS!
They are 'High Speed' engines and they will drive you crazy listening to them in short order!
The larger ones like Onan and Cat will have low speed engines that don't drive you crazy!
The live a lot longer too! The lower speeds of the engines meas the genset will last for years of constant use, were the lawnmower engine versions will crap out in short order.
(how many hours do you usually get out of a little lawn mower engine?)