Since you are customizing that case I can't stress this enough. BE CAREFUL screwing into the radiators. Too far and you can puncture the radiator. I mention this because by modifying things, distances can change... be careful mounting the radiators.
I am referring to the length of the screws more than anything. I poked through a Corair 115i AIO because I forgot a rubber washer.Everything is flat. I sanded/ground any metal that was poking out from drilling on the backside.