Did anyone do a G5 mod placing the motherboard vertically? (and by that I mean having the openings in the bottom).
I'm considering such a mod currently.
You keep the exterior of the G5 unchanged (maybe except for the ports at the back that you could put an aluminum strip over maybe with USB 3.0).
It accommodates larger motherboards, mounting it this way means you should be able to squeeze even an E-ATX board in.
Power-supply on top, but without a cutout, will be using the existing cutout at the bottom and an internal cable to the PSU on top.
Drives in optical bay compartment.
The main problem I see with this is that will be hard to find room for intake fans but then again this way the CPU fan would sit almost at the front anyway.