The Addtronics is basically the Supermicro 750's with a differnet face, Addtronics makes Supermicro's cases. Your post reminded me of that msv.
Man that width requirement I've only ever seen in the short wide and deep server cases. I have an Enlight case with triple redundant psu and enough width to park a VW and length out the wazoo but the height is that of a midtower.
Those are some tough specs

If I may ask, why not go with length instead of the height ?