512 player 5 round tournament.

first round: 16 gps of 32 players. (512 players) 31 game load, 3 day t/o.
second round: 8 gps of 16 players. (40 players) 30 game load, 7 day t/o
third round: 4 gps of 8 players. (16 players) 14 game load, 14 day t/o
fourth round: 2 gps of 4 players. (8 players) 12 game load, 14 day t/o
final round: 1 gp of two players. (2 players) 8 game load, 14 day t/o

The best in the group advances each round (any ties are chosen at random).

Such specific details may be very difficult for site admin to do; just throwing the idea out there.

really flexmre? why not just a 2 round tournament say gp size 20, that does 400 people and is simple, what a fool you are! flexmore you idiot!