I use the number 1 option myself. I seem to have a mental block about electricity so I've kept it simple. A fairly small generator ($400 predator at Harbor Freight) is enough to keep lights, tv's, big and small fridges and freezers going. When we replaced the A/C, after the inspection the installer added a pigtail so I can power the igniter and blower on our gas furnace.
For the once or twice a year we see outages of part of a day to a bit more, it works fine. No A/C and a bit of running around to hook up but cheap insurance.
That's the way the Majority of people do it. It's Cheaper. No Electrician or Special Wiring needed. And it's Portable.
For a Business, or for a Home Owner with a Larger Budget, a Dedicated Hardwired System does have Advantages. But it would have to be done right. And Not something an Average Home Owner should attempt.