I just been to Fungling bazzar of Taplejung not more than that......I think you can get maps on google.........I don't think you will get the street view like here at US. 
As far I know we took one pickup from Ktm to go there........u won't have anyproblem till Taplejung bazzar. While we were going (around one and half years ago), the road from Phidim bazzar to Taplejung bazzar was under construction. I think by this date most part of that road must have been paved. Ok best of luck and have safe journey...........Dherai rai maiya lai aankha lagauni hoina ni feri..............lolz...........