Installer GUI never loads

Motherboard: Asus P5Q3
Graphics: EVGA GeForce 9800 GTX
RAM: 4x2 GB
SATA: 750 GB, 1 TB, DVD-RW

Currently running OS X 10.5.6 which I installed over a year ago using a prepackaged OS X distribution (I don't recall which one). I'm trying to upgrade it to Snow Leopard (among other reasons, so I can actually sync my iPhone 4). I've looked at various methods for booting a retail copy of SL using Chameleon/PC-EFI on an 8 GB USB drive.

The most success I've had was restoring the SL DVD image to the memory stick, and installing just chameleon 2.0RC3 (or chameleon and PC-EFI 10.6) ontop of it. This solution boots to the GUI (verbose boot completes with nothing interesting written to the console), loads a gray screen with the black pointer cursor, which I have control of moving the mouse, and then the cursor changes to the spinning rainbow and never proceeds. I've tried various combinations of kexts(dsmos,fakesmc,applertc), in /Extra/Extensions, but none have produced better results, and some have caused earlier panicing

Since it boots without panicing, I'm thinking the issue isn't the bootloader, but I can't see what's going on (no logging available) once that gray screen loads, so I have no idea what's hanging it up.