So this is the prototype a friend has made that holds 8 GPUs, which will work well with the 16x 8 way splitter that is currently under development. This is NOT a final design and there are already a few things I want changed, but it's progress in the right direction. Welded aluminum frame and we're shooting for a selling price of $100 worth of GPUC.

Do you know what risers you will need for GPU in this setup, how long? I think more than 35cm.
although it looks nice, if it stays like that there will be major electrical problems (short circuits) as the motherboard is on an aluminium plate and might as well electrocute the user if it touches the frame also in aluminum when the power is turned on and the motherboard start to burn.
I think you have to make that the frame is grounded to avoid these sort of problem.
(you might want to check the regulation in north America before putting this on sale)
Plastic risers for the motherboard (I use cut up bic pens) It is what we all do.
There is ABSOLUTELY no reason to not having a thin plastic mat under the
motherboard. Yeah, I'm going to trust the exposed bottom of my motherboard
to some rigged plastic risers. Soon as I install more ram or touch anything,
flex, metal to metal fried hardware. This should be made out of plastic, hell,
you can buy plastic garage stackable storage shelving for cheap and hang the video cards
without having to worry about a metal frame.
Enough with prototype framing already. Show and sell us some cards!
And maybe some of these
http://www.hashratesolutions.com/products/6-pack-pci-e-powered-riser-card-60cm-24-usb-3-0-cable