Storm Front (4th ed) and Run & Gun + Chrome Flesh (strangely) have probably the biggest chuncks of info, but, granted, it is not enough. I am also runing a game maybe heading this way, and the lore is scarce indeed - it seems we may need a "Shadowrun Space" sourcebook at some point

On top of Boston Lockdwon (5ed) there is also the Boston Mini Adventures (PDF sold with the Shadowun Chronicles game) and a section on Boston in the Target: UCAS (2nd). That is all on Boston AFAIK.