It’s working great! I’m afraid I can’t remember quite everything I did to get there. However, my notes are online. Here’s the section of those notes containing links I found helpful. Especially helpful was this thread on Git.
And the declarative portion of my configuration is entirely available on Github. So are the custom packages I wrote (see the subfolder called that), but I don’t think you’ll need them. (They’re almost declarative. I’d like to make them part of nixpkgs but when I tried it wasn’t easy, and I don’t actually have evidence that anybody else needs them.)