You need an 8 PCI-E slot mobo. The MSI Big Bang Marshall comes to mind, it's expensive.
Otherwise MSI-Z77A-GD65 will run 7 cards without issue. Using power risers.
Last I checked AMD APUs didn't fit in a land grid array with 1155 pins....
The title of the thread is what "mobo/etc should I use", as in that is his priority. Who builds 8 cards rigs around a CPU. He can sell the thing for an intel if he feels like it.
If you want to be constructive offer up a mobo with an 8 pci-e slot AMD mobo for that CPU. Or can you not find one? smartass