As for the the business side, I have a prototype modular mining case being delivered this weekend that is made from aluminum, has holding space for up to 8 GPUs, slots for two PSUs and, of course, room for the motherboard.  The prototype will have round stock pillars that thread together to allow for stacking. Everything is made of aluminum that is rigid and supportive.  I have also contacted TMSI Industries, Inc. in Canada, to design and prototype an 8 way PCIe 16x USB splitter/riser.  It is comprise of a PCB that plugs into the 16x PCIe slot on the motherboard and a secondary PCB that attaches to the GPUs.  The splitter has 8 female USB 3.0 connector and the secondary PCB that attaches to the GPUs is SATA powered and has another female USB 3.0 connector.  This will allow for any motherboard with a single 16x slot to have the maximum amount of GPUs supported by the OS in service, without having to purchase an extremely expensive motherboard.  I was going to green light the project a few days ago, but the initial launch failure was a much more pressing issue.