Getting 12 of us online is an issue, but that's soemthing every league has to deal with - and there are 'auto-pilot' options for those that can't be there.
CBS Auction FAQ
or we could do something similar to how mmbt0ne did the NFL dynasty auction. Maybe even ask him if we can use his system. that would stretch it out over a month or however long we want to, and could let everyone be active for the auction.
NFL Auction Draft in SE
i think i'd prefer the mmmbt0ne system. releasing however many players a day we need to to fit it in the timeframe. single bid, silent auction ftw.