Try SAKIS for reasonable priced bowlback zouks - you can probably get one for £400 or $600 if you hunt around.
Original tuning CFAD.
So-called Irish, or flatback, zouks (or the even longer mandola as I like to call it)can be tuned any damn way you like basically as there is no firm tradition. Beware the people who will try to tell there is only one way to play, and that just happens to be the way they've been playing with their Planxty tribute band for the last 20 years.. Clearly if you want to play "proper" Greek bouzoui music you're in a different ball game. I've played ADAD, GDAE and GDAD, but whatever your strings and neck and fingers can handle. Double stopping ADAD is fun and sort of easyish way to play a melody with a bit more oomph - good for pub gigs, whereas with GDAE is easy to play a lot of standard strumming accompaniement. Buy two to avoid those embarrassing retune moments.... You can even fingerpick...I have to do this occasionally as the rest of the band I sometimes play with claim that I play too loud sometimes! The cheek!!