We could promote this proposal by sharing it with the community at http://twistypuzzles.com/forum/ they'd likely be interested
I think there is a difference between a forum and a SE site.
I would be fine running a forum and somebody proposing a SE site for my area of expertise.
I would even commit considering myself ending up answering more question than asking them.
One could also first ask a moderator of the site whether they allow this ad. This way, it might even end up in an officially supported (in terms of sticky) news threads instead of some chat topic.