I made the return trip (Japan - US) last summer in a Turbo Commander.
I'd definitely recommend going through Russia unless you have more range than I did (around 1,500nm in my case). Going through the Aleutians looks great on paper, but I wouldn't want to do it.
My longest leg was around 900nm, IIRC. Of course, there are NO alternates, so you need more range than might be obvious at first glance.