> but I think I'm going to give powerline networking a shot and
> take wireless out of the equation entirely.
I looked into that briefly a few years ago. From what I remember, it only works within a single circuit in your house. So if your "base unit" is upstairs on a different circuit (on a different breaker), then modules downstairs wont be able to see it properly or at all. It seems really limited to me.
GroovyMAME support forum on BYOAC