Its not important whether the races stats suit to an archer char, but more what is most immersive.
Breton: I recently played as Breton and I had lot of fun. Furthermore, many of the Dark Brotherhood Members are bretons and so I would really fit in (Vicente Valtieri, Antoinetta Marie, Mathieu Bellamont, and I think Lucien Lachance should have also been one because hes name is breton). But I don't know if it would get boring - I played a Breton that was in the DB the last time, even if he was more a necromancer.
Dark Elf: I think they are quite fitting to the dark brotherhood and I never played as one.
Nord: Not fitting at all, but it kind of excites me. There's no Nord in the DB as far as I know and it would be something different.
Wood Elf: The Classic for Archer. Fits to marksman but I dont know if a wood elf fits to the dark brotherhood that good.
What would you suggest? Im really unsure.