Scott,
After Katrina, I was out of commercial power for about a month. The company I work for placed a large diesel at my house for the duration and subsequently for Gustav and other storms. They can be a little slow getting out and there's no guarantee they will come-through in the future, so I decided to purchase one. I wanted a large unit that ran on natural gasand powered the entire house. This was going to cost around $6-8k with me doing some of the work. My house is plumbed for natural gas, so the only large electrical draw is the central air conditioner and I'd need at least a 15kw to start it. Hopefully your power will be restored soon, but summertime in south Louisiana where it will remain above 80F and high humidity at night, can be a real motivator and the price becomes a non issue. My wife asked what if we just picked up a couple of window unit a/c's and a smaller generator. I started looking into this and it was much cheaper - <$2k to run the entire house and a few small window units. Well, to make a long story short, and the whole point I'm getting at, I purchased a 7kw gasoline portable, but converted it to run on natural gas. I don't worry about finding gasoline or waiting in the long lines, price increases, etc.
I bought the conversion kit from these guys. They have some videos of similar setups to what I have. I don't worry about fuel, running gas out of the carb, storing gasoline, etc. The kit cost me around $250, fuel line was about $200 with quick fittings and the gen was around $1100. Throw in the window unit air conditioners, a small transfer switch, and miscellaneous electrical stuff and I'm still a good bit <$2k total. I put it to the test after Isaac. My power was out for 3 days. It worked so well, I didn't request one from work ( i also knew this was no Katrina and my power would be restored soon). The engine runs very smooth and exceptionally clean. It's easy to start and will still run on gasoline if necessary without having to make modifications.
Electrically, I back-feed my central air compressor unit circuit which is rated for 40amps. I leave all of my breakers on and have the convenience of turning lights and ceiling fans on or plugging something into any outlet, but do have to realize the limitations of a 7kw generator. I tested it running two window unit A/C's - 4KBTU & 10KBTU, 9 ceiling fans and attached light fixtures, one desktop computer, one 50 inch plasma TV, two full sized refrigerators, one freezer, and several small items like router, alarm clocks, etc. I was trying to push it to the limit and decided to heat a cup of water in the microwave at full power. The voltage and frequency took a slight hit as the generator rev'd, but stablized within a few seconds. While that was running, I ran a pot of water through the coffee pot ( another power hog) and that is where the voltage stayed good, but the 60Hz frequency couldn't recover. I will never run all of that stuff at the same time, but rest comfortably while it's running. Otherwise, I would be watching meters connected to it all the time.
If you're just trying to run a few appliances and don't get extended power outages much, my system could be a little overkill, but when gasoline becomes a real pain to fine and high priced, NG at about 1/4 the price for the same BTU's, everyday life can have a semblance of normality. I usually work alot after storms and needed something that my wife could handle without having to go searching for gasoline and handling heavy 5-6 gallon cans. If anyone has any need like this, I highly recommend it. My brother-inlaw did the same thing, but had a 100 gallon propane tank installed. He runs a grill and his 6kw generator. He has it topped off at the beginning of each hurricane season and he estimates it would run about two weeks straight.