@Popes Having done this? Ares is by far the easiest.
Channeling is a challenge though. From what I found there were a few options that didn’t involve starting from scratch:
Tat was generous enough to let me use the code for Spirit Lake with her magic system implemented with FS3. Had to do some modification but worked pretty great. Can check with her on that.
Fate plugin for Ares. The Dresden Files RPG is Fate based and really easy to adapt the magic system to channeling.
If you really don’t like Ares but are on board with the Fate system? Somewhere on the internet may still be the Dresden File RPG code for Penn or TinyMUX that was used to run that Dresden Files MU I forgot the name, but was fully implemented and pretty slick. Edit: Dark Spires was the name of the MU. The runner of it was active that that other MU board place but I’m not sure if they are here. They may know where to get the code if you ask around.