Long story short, I had 3 m2-atx, 2 of them won't survive engine crank.
So I replaced it with dsatx, but I already bought voompc 2 case.
After few hours of imagination and couple hours of fabricating:
The aluminum plate measurement :
7.3125" x 5.25" x 0.05"
It slides into the voompc top rail, no modification whatsoever to the original case.
The only downside is I only have 1 case fan now, fortunately temperature for my intel d201gly2a didn't go over 45C after a few hours of testing.
I might be able to help fabricate this attachment kit if anyone needs one.