For the past week or so I have been working on a case mod for my mythtv box. Basicly it is a $45 SHAW case from MSY. I have mounted the 5.1 amp in the front of the case. This required cutting the sides and lid of the box to create the stepped lid. I then altered the front panel by cutting part of it away and mounting it lower down (and 180deg around). All the cutting was done with an Ozito high speed rotary tool (aka Dremel)
It also has a customised disk mount section in the front. The final case has integrated IR receiver and IT transmitter and wireless mouse receiver.
I have also installed a Coolermaster Hyper TX cpu cooler which is working very well and I have cut some extra holes in the power supply so the cpu cooler blows directly into the power supply. I still need to find a better fan for the power supply.
Once I installed everything and had the machine running, I decided the hard disk was getting too hot tucked away under the cdrom. I built another mounting bracket to go on the right hand side and have mounted a 5V fan blowing onto the disk. This is working well.