if your case wont fit in a standard 19" server rack and wont even accept rails, advertising under the 4U scheme is meaningless. the only people who care about "U"s are people wanting to put stuff in a standard rack.
That said...
Hey!
OCTOMINER here. We have 4U cases in stock also and we offer international shipping.
We also have a new 12 GPU rig that has a 1151 socketed CPU, it can take up to 6 core i7 CPUs. Usually people spec it with a G3930.
We actually manufacture our own hardware to improve the reliability and functionality. For example our OCTOMINER VENTUS fans in our cases are even more efficient than Delta fans. We put extra effort in to get the fans as efficient as possible, the use double thick PCB boards, thicker copper coiling and imported IC chips and Japanese NMB double ball bearings. This helps bring the power draw down lower per rig and will also improve the lifespan of the fans.
I did a quick search and could not find any information about that 12-GPU board that would accept an i7. not on your website, and not anywhere else.
can you post links to the full specs?
what chipset?
how many PCIe lanes per slot?
will they run PCIe gen 3.0 in all slots?