I'd advise against the Phenom as a case-
The "M" versions of the three Bitfenix cases are awful. Most mATX boards use slots 1+2 for graphics cards, but some use 2+3 (using a PCIe x1 in slot 1). If you install an optical drive, you effectively block slots 3+4.
The graphics card(s) and cabled end of the PSU fight for space, so if one is long the other can't be, leading to confusion.
The maximum cooler height is also ambiguous as you can install HDDs on a bracket above the CPU, and these vary in thickness.
The PSU exhausts directly next to the main intake for the case. This main intake area is also a HDD mounting area.
That's just a few of the dubious design choices on that case.
As Goodeggray mentioned, the Asus Rampage IV Gene is pretty much your only option if you want to go for mATX.