Thank you all for your replies.
Unfortunately, I'm not very sure where to start looking for the Zenith Defy Xtreme Tourbillon (or Open, if Tourbillon is unavailable), unless googling for it.
Found two candidates so far: Replica Shop and 2009Watches, but I've been told they're most likely scam.
Finding a trustworthy dealer to make my purchase is still difficult for me. You guys have any advice? A member told me in a topic I created today, that there is an AD list somewhere. But still havent't found it yet.
In the meantime I'll try to talk to Andrew and Josh, and see what they think.