Lines, send 5 lines double angles included and people will vote on the best lines that can fill up a 3-5 minute video. Sure people might know what's in it but the same can be about the reel. Plus the edit with those lines can look entirely different depending the editor. Have 1 maybe 2 lines per skater depending on the amount of people who sign up and send clips and have votes on each line the skater sends.
One trick pony video, one trick 30+ skaters, 3-5 minutes of just one awesome trick per skater. I mean the one trick is going to be 9 seconds at the most with ramped slomos. And have double angles if necessary and/or ramped slomos.
Editors choice video, have people send clips marked with their names and doubles angles marked separately and post a link with all the clips amassed together and have the editors post their edit on the thread below your edit. Makes everyone happy and will more likely use each clip in case stuff doesn't get used.