Last week, I got a small package of J-hooks from SSS, which should complete the list of parts I need to drop the gas tank and install the poly replacement. Well, except for some kind of catchbasin for the gas I’ve already got. I’ll probably either siphon it into the Saturn or just go buy a Rubbermaid container.
I also found a post on the Binder Planet which has some more detailed instructions for running constant power to the head unit; unscrewing the fuse box should reveal two bus bars, one with switched power and one with constant. They each will accept female spade connectors, which means all I should need is a length of wire and the proper spade connector.