If you're trying to fit in with schools and unis etc, i think 27th november is probably the worst weekend, coz im not sure about other schools and stuff but thats the weekend before my end of semester testing week (this is at tafe)
can i suggest weekend of 18-19 september.. emphasis on the 19th, will be amusing for those who realise what day it is :D
Uni's exams finish on the 20th, ACT yr12 school exams are also due to finish before the 27th. Only TAFE/CIT seems to have exams after the 26th (if your right... I didn't check). Any later and we are into December and it's notoriously bad for attendance to hold LANs in December.