Hi Nate and welcome.
All what you said sounds good, I'll let those that know better comment on the electrics.
Pictured here are two banjos I built/converted with wooden tops, both cedar, they are thin so that they act like a banjo head. The small one is a current project. You could mount a piezo p/u in the back, now that's cheap.
In the banjo link you posted, I did not read it all, but the guy mentioned looking for lots of sustain. Just keep in mind that if you are considering playing a 5 string bluegrass type banjo the notes are normally quick an short, an over sustaining instrument may sound muddy or messy. Just a thought.
If'your using a top similar to what a banjo uses, I would recommend a low output humbucker. If your using a solid type thick material top I would go with something in the medium output humbucker.
Years ago I built an electric canjo and used a piezo disk glued under the top. This gives probably the most natural sound as it picks-up the vibration from the drum. Wiring wise, I put a volume knob on it and that's it.
The volume is wired in a regular fashion.
I got thinking about this last night and I'm wondering if banjo strings would work well with a magnetic pickup?
EMG makes a humbucker for Banjo's. Stewmac has them.