The repetitive weekly or bi-weekly is also a very interesting feature. There is already one in place called "spanishchallenge" and its a good success among existing members. In this case the idea with a high winner reward, would be to attract the media atention and even profesional or semmiprofesional writters. Nevertheless if the project get "selected" we can explore all posibilities and find the best one.
But the way, your idea/proposal/project is ammazing. You have my 100%

bR, Pablo