I have a 24 Kw natural gas Generac whole house backup. I don't think you need to power every single circuit in your home but if you want to, I suspect the 32 Kw will do the job. You may want to see what the wiring price difference between the 2 sizes is.
This was a flyer that I picked up from our local Costco and called them. The 27 kw was quoted at $21,000 installed and the 32 kw was $23,000 installed, but this is before the survey. It was an estimate, but wasn't materially different for me if it was slightly higher or lower once they look at it.
I had the survey for my 200A service that powers my home and pole barn and after working the numbers recommended a Generac 24kw natural gas unit installed for just under $10k, they included 7 years warranty and 0% financing.
The only issue is the wait time which is 8 months,,,,
