My original thought was two forums. One as it is.. open that anyone can post to, registered or not. The other was one that only registered members of the Qur'an Bible Group could post to.
I see this second one as being the place where "real" discussion takes place.. readable by everyone, but without interference of off topic comments.
Others could then respond or comment or question or debate to the open forum. People that do participate in that forum could then be invited (Christians by us, Muslims by Naaji and Omya) to join the Qur'an Bible Group and discuss "deeper" issues, which in the end, are the ones I would see as being the ones that lead to conversion.
Having said that, I am fully in agreement with Alpha, that whatever happens, we need to ensure that we are seen as public and not discriminatory in anyway.
I'm happy with whatever form we take, but I would love to do some very serious discussion here. I know muslims are being touched by what we are saying and I for one think time is ripe to see results for your long months of labouring for him through this forum.