If you need 6gpu rig go for h81 pro-g with some cheap celeron cpu, it's good mobo and runs fine just like h81 pro btc.
If you plan on running 5gpus or less you can use alternative from amd. FM2A88X+ is OK mobo and should be running fine with 5 GPU, but I prefer Gigabyte mobos like F2A55-DS3 rev 3.0. With cheap a4 or a6 apu (sometimes with a8 apu) power consumption is very close to intel alternative with 2 core celeron like g1840.
Also how about:
ASUS PRIME H270-PLUS
MSI H270 TOMAHAWK ARCTIC
they seem good boards with 6 pci-e slots