Yes, I've thought about Atelier Z as well, but who has one in stock? Even their own site doesn't show them.
Someones Mentioned LowEnd Jazz basses and i've heard nothing but good things about them so those seems like a good choice. Atelier Z also makes a six string that i've heard good things about. The body shape is a bit more modern but its just gives you better upper fret access. It may bit tough to get a hold of one because i think they are Japanese but you may be able to find one used around the forums. Here ar some pics i managed to find of Atelier Z 6ers.
[Invalid or Expired Link Removed]
Link Removed