Sammie and were discussin this a couple o weeks ago as a live action vid of this: https://www.youtube.com/watch?v=wFeQ0w3OR_U&playnext=1&list=PL10B283591E87C3EF
Fairly simple cosplays and a couple of us already have them from the group we cosplayed a while ago...
so....
Len: justhewaydrmademe
Rin: Sammie
Miku: Sqeakzilla??
Kaito: Clair??
would need some other girls too tho not necessarily meiko n luka as u see in the vid.. other vocaloids am sure is fine