The M2-ATX fits right in the front after you remove the Ac-dc power supply that comes with the case. (junk anyway)
I silicone glued a plastic protector to the back of the pcb to keep it from shorting on anything. I also used some sticky 2-sided rubber matting on the ends/sides to keep it from vibrating to death in there.
You will also notice that I had to cut and splice all the wires so there was room/empty space for items and airflow.