Hey Sacha, been on abit of a hunt for you. What do you make of this http://www.pistonheads.com/sales/1123595.htm ???
Pistonheads is a really good, if you have searched Atuotrader to death it'll make for a refreshing change.
Also try Imports Direct - http://dealerservices.autotrader.co.uk/134425/index.htm
this is where i got my Zed from, they are brilliant there and really helpful. I would highly recommend them. I just checked there website for black or blue Zeds and no luck but they dont advertise all their cars online and when i went they took me to their spare yard that had around an extra 50 Zeds in it was a sight for sore eyes i tell ya!! you could pretty much find whatever you wanted in there and there was definately black and blue Zeds there when i went.
Good luck and keep us informed on how your getting on.
Muttley