Lets see you need ...
http://www.varranger.fr/Gallery.phpLaptop
vArranger program
SD2 sound module
Controller keyboard
Lyric reader
If you sing a Vocal harmonizer unit also.
All this has to be bought and hooked up on a gig vs on each gig vs an All In One Arranger KB.......?
PS.. and if it doesn't work out for you has anyone ever seen a vArranger prog sold on Ebay?.... just saying?