Sounds very interesting. I havent met anybody to order a shooting of such an event with many people. For events like you described a one-shot-solution would be suitable... this means a little camera that can take the complete scenery with one shot. With these you could also take videos. The quality is good however not as highlevel as the shot above which is taken using 4 shots at very high resolution. I love goa partys... so lets go ;-)