Some questions that aren't answered by the first post and some genuine hints:
What's the reward for 1st place 2nd place and 3rd place? I mean... there has to be some
motivation for people to enter such a complex event, right?
Why do you think it is a good idea to level up 7 characters when it takes about a month or more to get to level 145+?
Why is it SP only, when you can just go to HC on the server? On the sin war, everybody will see the hc ladder statistics and nobody can cheat. (Unless somebody deletes a character, but I'm sure the aahz could just look into it if anybody decides to delete a character and try again.)
I'm not sure, but has anyone yet said they'd be interested in that kind of event aside from you? If not, you might want to make a visually pleasing first post instead of a generic topic like this that neither catches any attention nor looks like a serious approach. Clear structure would be great as in: Introduction, Rules, Point system, and so on... If you want people to participate, make it clear you're hosting the event instead of "Maybe somebody is interested? Maybe not?" That just confuses people. Or rather, they lay back and watch until you actually host it before giving an opinion.
There were some events before and to get an idea on how to structure it well enough to make people get interested in that event, here are some examples: viewtopic.php?f=25&t=50579viewtopic.php?f=25&t=41866
You can just press the "Quote" button on the bottom right corner to see the BBcodes they used if that's some knowledge you're missing to make the post look important.
Also, if you contact the admins I'm sure they'd love to support this event if hosted on the server. In the worst case, they'd be able to help you make it work if it's special loot as a price is what you're missing.