A scheduling idea, if real time interaction is of importance, which it does seem to be - presence . . .

1/ People post their own times they would like to meet. Here's one free online tool that simplifies a group doing this:

Easy scheduling | Doodle

After people have done that, it should become apparent where the overlaps are, and then decisions can be made as to whether one meeting suffices for everyone, or perhaps 2 or 3 different groups are needed, say each with set participants, perhaps.

2/ Online meeting systems can be used for meetings, with our without webcams. Obviously faces provide rich information when people speak, and equally obviously some people don't want their face or perhaps even voice, shown. Depends how you define "online" for the purposes of your meeting.

Skype, I believe can be used for group meetings, and Google hangout for sure. I gave seen hubby using this for work. He says it's easy, but warns you'll need fake Google+plus account, because Google tracks you and insists on a lot of personal info if you use Google+, so there are issues to consider there.

So, an attempt to provide some technical info that might be relevant to the problem at hand. As I won't be in the group at the start, I have no horse in this race.

Edit: having read the last few posts, I see there is already a time and place for the moment, but I'll leave this here for any future use it might have.