X58 is too old and is likely limited to 5-6 GPUs.
H97 should work though. Does it even boot with more than 6 GPUs? If it does, your OS is likely the issue.
You might be able to get 5-6 cards with the small boards, but YMMV. The chipset doesn't really matter I think, the multiplier combines the signal of all 4 cards into 1 lane.
I've ran 7 on an old X58 board using a PCIe port multiplier card under Windows 7. Ran perfectly fine for weeks.