Actually, I have access to a metal workshop but not a wood one at the moment, so the bridge build is the most accessible one for me at the moment! And, I think it'll be a pretty cool piece of machinery... It's obviously inspired more than just a little by Atlansia http://www.atlansia.jp/ATG.05.JPG and the really cool thing is that it is entirely modular. Just use different base plates for tremolo/fixed, 6-string, 7-string, 8-string, fanned frets, etc.
The original plan was to have it made in stainless steel, but I think I will try Aluminum and see how it goes. It will require hardened inserts for the fulcrum edges on a tremolo version, but I'll work it out in one way or another. Next challenge is to make it locking like the Steinberger bridges (i.e. lock into place like a fixed bridge, not the strings)