Well after weeks of deciding what I wanted and trying to figure out how to install it, I finally put my new head unit in yesterday. Thanks to everybody who offered up help on powering it and what not.
I was a little upset after I got it put in -- AM radio reception sounded like crap. FM was better, but not great. I finally got to thinking about it at lunch today and pulled it out again to look around. It turns out the metal outside edge of the antenna adapter that came with my GM-035 wiring harness was rubbing against the metal case of the stereo and making noise every time it did. I just wrapped the adapter and end of the antenna cable with electrical tape, and also taped it to the unit itself so it stayed plugged in as it should. Clear as a bell now! Woohoo!
Another sucessful class 2 bypass