Anything less than 48kw is essentially unheard of in new construction in the US, and even old houses with 24kw service are getting upgraded. Less than 24 is considered essentially unsellable.
Same thing. If your house was built after WW2 it will usually have 200a service if you're all electric, and maybe 150 if your heat is non-electric. Most older houses have also been upgraded at this point too. It's not uncommon for larger houses to have 400a (96kw) service.