Possible issue is the hardware detection. The external drive would need to show up in the same location every time (like /dev/sda or similar). You may need to keep the same configuration every time you boot (not move USB/Firewire plugs around).
**CRY** Hardware detection is correct! I have the new drive hooked up, and windows sees it perfectly. Slap the VL6 (Standard) install CD in, it fires up, and it can't see /dev/sdb. However, if you bug out of the install and go to gpartd, it DOES see the USB drive. Is there a command string that I can give at the start of the install disk to tell it to find sdb1?