It can take a while to find the right team -- I had to interview five cabinet makers before I found one even willing to use the reclaimed wood!

While I can't tell you exactly what to do, not knowing all the logistics involved in your particular site, here's how you might proceed: keep looking for a local highly-custom cabinet maker who can think outside the box. Also find a metalsmith who can spec tubing diameters, allthread, and hardware to order, as well as mill or weld up any hidden brackets required. You want someone who will be able to conceptualize the thing as a whole, given existing ceiling or roof framing, adjacent walls or places your space may have to hide lateral bracing, where the electricity is coming from, where to find specialty items like hinges and magnets for the glass doors (I used mcmaster.com a lot), and so forth.

Remember if your goal is the suspension and transparency, your cabinetmaker may have alternative ways of achieving it -- ways that work better with your shelf proportions, ceiling height, materials at hand, available labor etc. Also, know that with small, highly custom, site-specific work like this, the design costs can be as much as the materials and labor.

Best of luck!