Finally got the board up and running today, and I have a reliable install routine. I figured out that the key was to interrupt the process at a specific point before it started installing everything so that I could shoehorn the Envy installer in before LMCE broke everything.
Anyways, I'm going to make a disc image (just in case, since it took so long to get a reliable routine up and running), so if someone mimics my hardware, it should be pretty easy for them to get up and going.
Waiting on more parts, but that bit of good news means that the demo is on, and it should be a good show.