1. Yeah, I had that set.
2. Wait, there's a difference between PC EFI and Chameleon? I had them both set. I found absolutely no documentary on PC EFI.
3. No, I just tried putting it into E / E.
4. I was using Slayer's it didn't seem like there'd be a big difference in them.

EDIT: Just read you only have to replace the boot file to switch between the two. Let me try that.

EDIT2: The PC EFI just instantly panics. I'm back at Chameleon because that actually gets some text going before halting at the AICPUPM kext. I put null back into /Extra and tried removing the AICPUPM kext from S/L/E and still nothing. About to try with your dsdt.

EDIT3: Okay, after editing the smbios to have a product name of macpro2,1, using your dsdt, editing boot.plist with my device-properties and resolution, then finally adding the 295 kext I found in my previous post to /Extra and S/L/E, it actually got past the AICPUPM kext and booted into the GUI. The video was laggy, and there was about an 1.5" border of black around the screen, but it was set to the 1600x900 resolution I specified in boot.plist. Any ideas how to get it running full now?