Thanks Roel for your comments.
I've committed myself to a VoiceWorks, but haven't yet received it. The one offered had Operating System 1.05 and I wanted the latest,1.09 installed. I've noted the comments about vocalisers and the KN7000 on various forums and decided to go this way after looking at and using DigiTech Vocalist Performer(actually purchased and then returned it).
regards
Keith