This isn't an exact science...the idea is to settle on a good brand that's affordable, then get the most output for the money. If a 6,000 Watt only costs $800...then great.
But if they get the water and sewage up soon...and power up by the 24th like they are saying...it might not be necessary to go through the ordeal right now.
Well it kind of is an exact science. Why run a generator with more HP, Watts and suck up more gas than needed?
If you need the watts then by all means.
I lived through a few weeks with a 12 hp Briggs running outside my rear porch. Had to fill the BIG gas tank several times in 24 hours, I was never so happy then when the damn thing turned off. They are LOUD!
Multiply that but sever neighbors run similar units,
See what the RUN tome is at 50% load, calculated how much gas you are gonna need. check the noise output.
You asked a question but
You want what you want, so just buy the cheapest one you can find.