We have the same problem in a Lian Li PC-Q18B that is currently in disuse because of my recent upgrades, but we plan to use it again soon. Do they make 12 volt EXTERNAL PSUs in the 300-350 watt category (or higher)? Replacing the PSU hole with a blank panel, with just a barrel connector, and putting one of those DC-DC converter boards in for the 3.3 and 5, would free up tons of space.