Commercial doesn't mean BIGGER. A generator rated as Commercial could be because of many reasons such as overall build configuration, voltage, number of phases and options or accessories.
For example we have a 6Kw DC gen commonly used for off grid and telecom towers or a 80kw propane, 600v 3p with the optional life safety package. Both are Commercial. Yet a 100kw diesel, 1p, 120/240v, enclosed level two with double wall base tank is not commercial.
Some customers will demand a Commercial type gen for residential use simply because of the application. Perhaps they need big integrity in the build due remote placement and future service will be challenging.
We stock 14kw and up in 3p 208v along with transfer switches from 100amp and up.
Call and review your needs to see if Commercial is the right fit for your application.