Just to jump in, before we decide on duration - maybe monthly is all we need - We could get something up and ready within a week because this first year we'll be dealing with almost 30 years of fanfic. Once we see what kind of volume we may have we can plan from there ..?
If there is anyone who would like to help with this please let us know because the more the merrier! I'm going to look a little more into how the other fandom (Twilight) does it and see what we can learn from them .. sound like a start?