To be honest, I havent really read this through, but why can't you you bang a 2x120 in the bottom where the HDD cage is? That would have been my go to solution.
Well then I would have to mod the front, as there is absolute no venting in that part of the case, plus the PSU and cables there from take up almost all the available space. I hope I during the coming week can finish the build for now just as an air cooled rig until I see what to actually do about it.