A few points I would like to make, and please be tolerant with me if I sound curt, as typing is difficult.
1. Despite my efforts Brian has never shown the least interest in the Challenges, so I doubt he would wish any direct connection between such an anthology and the site.
2. You won't get an editor with the sort of name that would lend the anthology the kind of credibility everyone seems to be hoping for in an editor unless you give him/her full editorial control -- including which stories stay and which stories go. You would not get such an editor and be able to set out in advance what he or she may or may not do in the way of editing. Absolutely. Non-negotiable. Whose name goes on the cover? The editor's. Whose reputation is on the line? The editor's. The editor will be protective of both.
3. The editor would not, under any conditions, be me. See reasons above, and consider what it would do to my place in the community if I exercised full editorial control. I already have a reputation as a draconian moderator. Such good will as remains toward me I would like to keep.
4. The anthology will not make money. Anthologies sell well enough to turn a profit because the editor has a name and several of the contributors have big names. As far as I remember, the biggest name contributors you have (to date) are Toby and I. You need two or three names much bigger, with ours tagged on at the end. Do this because you want to do it, not because you expect to make money.
5. Despite what Ursa says, your stories are not now in the public domain. Site rules are clear that you retain copyright to everything posted here, and we have a copyright notice in the first message of each Challenge, so that anyone who comes along and wants to copy the stories cannot plead "I didn't know."
I hope you all understand what I mean and no one is offended, because it really would wear me out to get into a discussion about any of this.