I simply use $60 MSI mATX h61-p21 boards. I have two of them and each runs 4x5870s. If you're going to use 4x7970s I may consider putting them on risers with Molex plugs.
That looks like a pretty good miner platform for those with extender cables, as it is all PCIe 1x slots with no legacy PCI, and a Celeron G440 can go in that ($65+$41 free ship on NewEgg). I started looking at AMD boards figuring that a Sempron plus the least-expensive brand-name 4xPCIe motherboard would be cheaper than an Intel platform.
For later resell though, a motherboard with two 16x PCIe slots plus a 2.8GHz AMD CPU will sell easier than a mATX no-PCI-slot board with a 1.6GHz Celeron - you can sell the AMD with GPUs as a crossfire gaming system, but the Intel can't even be a media PC (only VGA out).
that is tru, but the 2 I listed has on mobo start and reset buttons for caseless rigs.
I've got your reset switch right here:
For power, just set the BIOS to power on after power loss.
I have two of those boards with G440s. I had to flash the bios for the boards to post with the G440s, but it was extremely simple. Other than that they have been working fine. I use a screwdriver to start the machines as well.