When this started I thought people just meant a new section on these forums for users to talk about and criticise their comics. If anything bigger is going to be done make sure you have the organisation and the planning to back it up, or it might become like the Ozy and Millie game project.
But making a forum is a helluva lot easier than making a game

I think jack is right....don't under estimate how large of a project your talking about. Particularly if you want some of the features like described above (like being able to host user strips). Building a good forum is not just taking some already built PHP code and throwing it to a database. You need to find good forum software you like, modify it to fit your image and needs, provide additional features and reasons to come to your site, deal with search engines and page ranking, then setup a forum and user structure.
Granted you have a lot of the hurdles out of the way since I can host you guys on ether a sub-domain or fully-qulified domain. But you still need to develope a strong user command structure. If you want me to host then someone needs to come to me as the admin of this project so we can talk over ideas and I can set you up with what you need.
Personally from the view point of being a member and leader of several projects like this I would recomend for the time being requesting and using an additional forum board on DC. Then you can spend the time to develope a user structure to find out who will be leading this group. Also that will give you time to start working on the site. It will take some time to develope and build the site anyways so this will provide a medium of chat durring the time of design and build before the site is ready to let the flood of people on.