Spark & 2talk will do. You do need your primary offer to be with them too though.

IMO it's the best way to deliver voice to residential customers. At least then they can use whatever router they want.

https://www.geekzone.co.nz/forums.asp?forumid=49&topicid=174969 - Assuming that it's all still up to date (I'm happy to edit if not). I'll need to add 2talk!