I would say 8 People each tournament would be fine, as the Jord said. That would be 7 Rounds. As soon as all opponents are chosen, we can fix dates induvidually, I think.
Afterwards, we can declare results here, and write the tournament report

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This guy redid our computer and now I can't play

Do you think we can solve that problem? If not, maybe you can use another PC eg in the Library, in the Internet-Cafe, at Public Computers, or you might try to use one of your sibblings Computers, or abuse those in school...
Why can not you run gccg?