pf9 looks interesting, although it took a bit of hunting to find it (largely because it has the same name as a gun!).
My worry right now is that it won't work with the newest plan9port, since it hasn't been updated since last year.
What I probably need to do is just make my own port and keep it in sync with the GitHub repo, since the vibe I'm getting is that most of the stuff that needs changing is stuff that I'm not going to use, and the rest of the stuff resides in headers.
Thanks to all who answered!