Let's see:
- Steve
- Faye
- Dora
- Sven
- Amir
- Jimbo (if he's sober)
- Hannelore
- Angus
- Cosette
- Elliot
- Penelope
- Will
- Marigold
- Emily (obviously)
- Gabby (getting there)
- Claire (who's probably already going to be there)
- Clinton (though that's questionable)
- Momo
- Winslow
Pintsize (No, he doesn't want him to burn Emily's parents place down)
Hmm... Jimbo and Winslow probably wouldn't fit in. I don't think Marten ever really thinks of Amir outside Deathmřle. I almost forgot who Eliot was. Penelope's probably not going, or Wil, just by virtue of being too many degrees from the principals. I don't think Marten would think to invite Sven, and I don't think Dora would want to. Angus and Cosette are probably invited by default, though.
So yeah, I'm going to say in addition to Dora and Faye, Angus, Steve, Cosette, Hannelore, Marigold, Momo, and of course, Emily, Gabby, Claire, Marten, and Tai. Probably not Clinton, only since the only one who'd invite him would be Claire, and she... wouldn't.